diff --git a/demos/surface/src/main/AndroidManifest.xml b/demos/surface/src/main/AndroidManifest.xml
index fab5b2070c..9e9cbeed5c 100644
--- a/demos/surface/src/main/AndroidManifest.xml
+++ b/demos/surface/src/main/AndroidManifest.xml
@@ -22,12 +22,14 @@
   <uses-sdk/>
 
   <application
-    android:allowBackup="false"
-    android:icon="@mipmap/ic_launcher"
-    android:label="@string/application_name"
-    android:exported="true">
+      android:allowBackup="false"
+      android:icon="@mipmap/ic_launcher"
+      android:label="@string/application_name"
+      android:exported="true">
 
-    <activity android:name=".MainActivity">
+    <activity
+        android:name=".MainActivity"
+        android:exported="true">
       <intent-filter>
         <action android:name="android.intent.action.MAIN"/>
         <category android:name="android.intent.category.LAUNCHER"/>
diff --git a/extensions/cast/build.gradle b/extensions/cast/build.gradle
index 3addcceaef..ba333edbe2 100644
--- a/extensions/cast/build.gradle
+++ b/extensions/cast/build.gradle
@@ -14,7 +14,7 @@
 apply from: "$gradle.ext.exoplayerSettingsDir/common_library_config.gradle"
 
 dependencies {
-    api 'com.google.android.gms:play-services-cast-framework:20.1.0'
+    api 'com.google.android.gms:play-services-cast-framework:21.0.1'
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
     implementation project(modulePrefix + 'library-common')
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
diff --git a/extensions/cronet/build.gradle b/extensions/cronet/build.gradle
index 09211ca4cb..f179fac8e2 100644
--- a/extensions/cronet/build.gradle
+++ b/extensions/cronet/build.gradle
@@ -20,7 +20,7 @@ android {
 }
 
 dependencies {
-    api "com.google.android.gms:play-services-cronet:17.0.1"
+    api "com.google.android.gms:play-services-cronet:18.0.1"
     implementation project(modulePrefix + 'library-common')
     implementation project(modulePrefix + 'library-datasource')
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
diff --git a/extensions/ima/build.gradle b/extensions/ima/build.gradle
index 4a40f0afc9..95644aa368 100644
--- a/extensions/ima/build.gradle
+++ b/extensions/ima/build.gradle
@@ -25,7 +25,7 @@ android {
 }
 
 dependencies {
-    api 'com.google.ads.interactivemedia.v3:interactivemedia:3.25.1'
+    api 'com.google.ads.interactivemedia.v3:interactivemedia:3.26.0'
     implementation project(modulePrefix + 'library-core')
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
diff --git a/extensions/media2/src/androidTest/java/com/google/android/exoplayer2/ext/media2/SessionPlayerConnectorTest.java b/extensions/media2/src/androidTest/java/com/google/android/exoplayer2/ext/media2/SessionPlayerConnectorTest.java
index 755d62fc84..4a22f4e216 100644
--- a/extensions/media2/src/androidTest/java/com/google/android/exoplayer2/ext/media2/SessionPlayerConnectorTest.java
+++ b/extensions/media2/src/androidTest/java/com/google/android/exoplayer2/ext/media2/SessionPlayerConnectorTest.java
@@ -924,8 +924,7 @@ public class SessionPlayerConnectorTest {
     assertThat(onPlaylistChangedLatch.getCount()).isEqualTo(1);
   }
 
-  // TODO(b/168860979): De-flake and re-enable.
-  @Ignore
+  @Ignore("Internal ref: b/168860979")
   @Test
   @LargeTest
   public void replacePlaylistItem_calledOnlyOnce_notifiesPlaylistChangeOnlyOnce() throws Exception {
diff --git a/library/common/src/main/java/com/google/android/exoplayer2/HeartRating.java b/library/common/src/main/java/com/google/android/exoplayer2/HeartRating.java
index b656d0bd35..8520125c38 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/HeartRating.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/HeartRating.java
@@ -100,7 +100,7 @@ public final class HeartRating extends Rating {
 
   private static HeartRating fromBundle(Bundle bundle) {
     checkArgument(
-        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_DEFAULT)
+        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_UNSET)
             == TYPE);
     boolean isRated = bundle.getBoolean(keyForField(FIELD_RATED), /* defaultValue= */ false);
     return isRated
diff --git a/library/common/src/main/java/com/google/android/exoplayer2/PercentageRating.java b/library/common/src/main/java/com/google/android/exoplayer2/PercentageRating.java
index 1953e7e1d1..3bdb1dd11c 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/PercentageRating.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/PercentageRating.java
@@ -96,7 +96,7 @@ public final class PercentageRating extends Rating {
 
   private static PercentageRating fromBundle(Bundle bundle) {
     checkArgument(
-        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_DEFAULT)
+        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_UNSET)
             == TYPE);
     float percent = bundle.getFloat(keyForField(FIELD_PERCENT), /* defaultValue= */ RATING_UNSET);
     return percent == RATING_UNSET ? new PercentageRating() : new PercentageRating(percent);
diff --git a/library/common/src/main/java/com/google/android/exoplayer2/Rating.java b/library/common/src/main/java/com/google/android/exoplayer2/Rating.java
index 0477bbce0e..69886aafc3 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/Rating.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/Rating.java
@@ -41,7 +41,7 @@ public abstract class Rating implements Bundleable {
   @Documented
   @Retention(RetentionPolicy.SOURCE)
   @IntDef({
-    RATING_TYPE_DEFAULT,
+    RATING_TYPE_UNSET,
     RATING_TYPE_HEART,
     RATING_TYPE_PERCENTAGE,
     RATING_TYPE_STAR,
@@ -49,7 +49,7 @@ public abstract class Rating implements Bundleable {
   })
   /* package */ @interface RatingType {}
 
-  /* package */ static final int RATING_TYPE_DEFAULT = -1;
+  /* package */ static final int RATING_TYPE_UNSET = -1;
   /* package */ static final int RATING_TYPE_HEART = 0;
   /* package */ static final int RATING_TYPE_PERCENTAGE = 1;
   /* package */ static final int RATING_TYPE_STAR = 2;
@@ -68,7 +68,7 @@ public abstract class Rating implements Bundleable {
   private static Rating fromBundle(Bundle bundle) {
     @RatingType
     int ratingType =
-        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_DEFAULT);
+        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_UNSET);
     switch (ratingType) {
       case RATING_TYPE_HEART:
         return HeartRating.CREATOR.fromBundle(bundle);
@@ -78,8 +78,9 @@ public abstract class Rating implements Bundleable {
         return StarRating.CREATOR.fromBundle(bundle);
       case RATING_TYPE_THUMB:
         return ThumbRating.CREATOR.fromBundle(bundle);
+      case RATING_TYPE_UNSET:
       default:
-        throw new IllegalArgumentException("Encountered unknown rating type: " + ratingType);
+        throw new IllegalArgumentException("Unknown RatingType: " + ratingType);
     }
   }
 
diff --git a/library/common/src/main/java/com/google/android/exoplayer2/StarRating.java b/library/common/src/main/java/com/google/android/exoplayer2/StarRating.java
index 543228185e..05736766b5 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/StarRating.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/StarRating.java
@@ -125,7 +125,7 @@ public final class StarRating extends Rating {
 
   private static StarRating fromBundle(Bundle bundle) {
     checkArgument(
-        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_DEFAULT)
+        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_UNSET)
             == TYPE);
     int maxStars =
         bundle.getInt(keyForField(FIELD_MAX_STARS), /* defaultValue= */ MAX_STARS_DEFAULT);
diff --git a/library/common/src/main/java/com/google/android/exoplayer2/ThumbRating.java b/library/common/src/main/java/com/google/android/exoplayer2/ThumbRating.java
index 07e0ee38d3..cc4b404f2c 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/ThumbRating.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/ThumbRating.java
@@ -97,7 +97,7 @@ public final class ThumbRating extends Rating {
 
   private static ThumbRating fromBundle(Bundle bundle) {
     checkArgument(
-        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_DEFAULT)
+        bundle.getInt(keyForField(FIELD_RATING_TYPE), /* defaultValue= */ RATING_TYPE_UNSET)
             == TYPE);
     boolean rated = bundle.getBoolean(keyForField(FIELD_RATED), /* defaultValue= */ false);
     return rated
diff --git a/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java b/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
index 1a961d0585..b21b247f76 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
@@ -2405,6 +2405,8 @@ public final class Util {
         return "camera motion";
       case C.TRACK_TYPE_NONE:
         return "none";
+      case C.TRACK_TYPE_UNKNOWN:
+        return "unknown";
       default:
         return trackType >= C.TRACK_TYPE_CUSTOM_BASE ? "custom (" + trackType + ")" : "?";
     }
diff --git a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java
index 6bdc84438b..28f40c8506 100644
--- a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java
+++ b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java
@@ -109,8 +109,7 @@ public class DownloadManagerDashTest {
     testThread.release();
   }
 
-  // Disabled due to flakiness.
-  @Ignore
+  @Ignore("Disabled due to flakiness")
   @Test
   public void saveAndLoadActionFile() throws Throwable {
     // Configure fakeDataSet to block until interrupted when TEST_MPD is read.
diff --git a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java
index e8a71798be..b50d25414d 100644
--- a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java
+++ b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java
@@ -157,7 +157,7 @@ public class DownloadServiceDashTest {
     testThread.release();
   }
 
-  @Ignore // b/78877092
+  @Ignore("Internal ref: b/78877092")
   @Test
   public void multipleDownloadRequest() throws Throwable {
     downloadKeys(fakeStreamKey1);
@@ -168,7 +168,7 @@ public class DownloadServiceDashTest {
     assertCachedData(cache, fakeDataSet);
   }
 
-  @Ignore // b/78877092
+  @Ignore("Internal ref: b/78877092")
   @Test
   public void removeAction() throws Throwable {
     downloadKeys(fakeStreamKey1, fakeStreamKey2);
@@ -182,7 +182,7 @@ public class DownloadServiceDashTest {
     assertCacheEmpty(cache);
   }
 
-  @Ignore // b/78877092
+  @Ignore("Internal ref: b/78877092")
   @Test
   public void removeBeforeDownloadComplete() throws Throwable {
     pauseDownloadCondition = new ConditionVariable();
diff --git a/library/ui/src/main/java/com/google/android/exoplayer2/ui/PlayerNotificationManager.java b/library/ui/src/main/java/com/google/android/exoplayer2/ui/PlayerNotificationManager.java
index 462da93a6c..abb554855b 100644
--- a/library/ui/src/main/java/com/google/android/exoplayer2/ui/PlayerNotificationManager.java
+++ b/library/ui/src/main/java/com/google/android/exoplayer2/ui/PlayerNotificationManager.java
@@ -1478,6 +1478,7 @@ public class PlayerNotificationManager {
     return actions;
   }
 
+  @SuppressWarnings("UnspecifiedImmutableFlag") // Warning is spurious.
   private static PendingIntent createBroadcastIntent(
       String action, Context context, int instanceId) {
     Intent intent = new Intent(action).setPackage(context.getPackageName());