Copy from V1: Extractor.release() method releases all kept resources.

This method is needed by FlacExtractor to release native resources.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=119143922

library/src/main/java/com/google/android/exoplayer/extractor/Extractor.java

@@ -97,4 +97,8 @@ public interface Extractor {
    */
   void seek();
 
+  /**
+   * Releases all kept resources.
+   */
+  void release();
 }

library/src/main/java/com/google/android/exoplayer/extractor/flv/FlvExtractor.java

@@ -119,6 +119,11 @@ public final class FlvExtractor implements Extractor, SeekMap {
     bytesToNextTagHeader = 0;
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition) throws IOException,
       InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/mkv/MatroskaExtractor.java

@@ -272,6 +272,11 @@ public final class MatroskaExtractor implements Extractor {
     resetSample();
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition) throws IOException,
       InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/mp3/Mp3Extractor.java

@@ -110,6 +110,11 @@ public final class Mp3Extractor implements Extractor {
     sampleBytesRemaining = 0;
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/mp4/FragmentedMp4Extractor.java

@@ -169,6 +169,11 @@ public final class FragmentedMp4Extractor implements Extractor {
     enterReadingAtomHeaderState();
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/mp4/Mp4Extractor.java

@@ -106,6 +106,11 @@ public final class Mp4Extractor implements Extractor, SeekMap {
     parserState = STATE_AFTER_SEEK;
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/ogg/OggVorbisExtractor.java

@@ -93,6 +93,11 @@ public final class OggVorbisExtractor implements Extractor, SeekMap {
     scratch.reset();
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/ts/AdtsExtractor.java

@@ -121,6 +121,11 @@ public final class AdtsExtractor implements Extractor {
     adtsReader.seek();
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/ts/PsExtractor.java

@@ -120,6 +120,11 @@ public final class PsExtractor implements Extractor {
     }
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/ts/TsExtractor.java

@@ -123,6 +123,11 @@ public final class TsExtractor implements Extractor {
     }
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {

library/src/main/java/com/google/android/exoplayer/extractor/wav/WavExtractor.java

@@ -58,6 +58,11 @@ public final class WavExtractor implements Extractor, SeekMap {
     pendingBytes = 0;
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {

library/src/main/java/com/google/android/exoplayer/hls/WebvttExtractor.java

@@ -86,6 +86,11 @@ import java.util.regex.Pattern;
     throw new IllegalStateException();
   }
 
+  @Override
+  public void release() {
+    // Do nothing
+  }
+
   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {