Add RawResourceDataSource test for android.resource:///id URI

This is the documented format of this URI. The previous test was
exercising an undocumented format. Support for the previous format is
kept (and documented) because it seems to be relatively common (despite
the package name not being needed or used).

PiperOrigin-RevId: 573756190

libraries/datasource/src/androidTest/java/androidx/media3/datasource/RawResourceDataSourceContractTest.java

@@ -78,12 +78,12 @@ public final class RawResourceDataSourceContractTest extends DataSourceContractT
             .build(),
         new TestResource.Builder()
             .setName("android.resource:// with ID")
-            .setUri(
-                Uri.parse(
-                    "android.resource://"
-                        + ApplicationProvider.getApplicationContext().getPackageName()
-                        + "/"
-                        + R.raw.resource1))
+            .setUri(Uri.parse("android.resource:///" + R.raw.resource1))
+            .setExpectedBytes(RESOURCE_1_DATA)
+            .build(),
+        new TestResource.Builder()
+            .setName("android.resource:// with (unused) package and ID")
+            .setUri(Uri.parse("android.resource://unused.package.name/" + R.raw.resource1))
             .setExpectedBytes(RESOURCE_1_DATA)
             .build());
   }

libraries/datasource/src/main/java/androidx/media3/datasource/RawResourceDataSource.java

@@ -51,6 +51,11 @@ import java.nio.channels.FileChannel;
  *       efficient.
  * </ul>
  *
+ * <p>URIs of the form {@code android.resource://package/id} are also supported, although the
+ * package part is not needed and is not used. This support is due to this format being prevalent in
+ * the ecosystem (including being <a href="https://stackoverflow.com/a/4896272">recommended on Stack
+ * Overflow</a>).
+ *
  * <p>{@link #buildRawResourceUri(int)} can be used to build supported {@link Uri}s.
  */
 @UnstableApi