Fix build.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=123958609

library/src/main/java/com/google/android/exoplayer/chunk/ChunkTrackStream.java

@@ -169,7 +169,6 @@ public class ChunkTrackStream<T extends ChunkSource> implements TrackStream,
    * This method should be called when the stream is no longer required.
    */
   public void release() {
-    released = true;
     chunkSource.release();
     sampleQueue.disable();
     loadControl.unregister(this);