Rename HlsPlaylistTracker's release to stop

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=202103550

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaSource.java

@@ -401,7 +401,7 @@ public final class HlsMediaSource extends BaseMediaSource
   @Override
   public void releaseSourceInternal() {
     if (playlistTracker != null) {
-      playlistTracker.release();
+      playlistTracker.stop();
     }
   }
 

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/DefaultHlsPlaylistTracker.java

@@ -105,7 +105,7 @@ public final class DefaultHlsPlaylistTracker
   }
 
   @Override
-  public void release() {
+  public void stop() {
     primaryHlsUrl = null;
     primaryUrlSnapshot = null;
     masterPlaylist = null;

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/HlsPlaylistTracker.java

@@ -100,8 +100,8 @@ public interface HlsPlaylistTracker {
   /**
    * Starts the playlist tracker.
    *
-   * <p>Must be called from the playback thread. A tracker may be restarted after a {@link
-   * #release()} call.
+   * <p>Must be called from the playback thread. A tracker may be restarted after a {@link #stop()}
+   * call.
    *
    * @param initialPlaylistUri Uri of the HLS stream. Can point to a media playlist or a master
    *     playlist.
@@ -111,8 +111,12 @@ public interface HlsPlaylistTracker {
   void start(
       Uri initialPlaylistUri, EventDispatcher eventDispatcher, PrimaryPlaylistListener listener);
 
-  /** Releases all acquired resources. Must be called once per {@link #start} call. */
-  void release();
+  /**
+   * Stops the playlist tracker and releases any acquired resources.
+   *
+   * <p>Must be called once per {@link #start} call.
+   */
+  void stop();
 
   /**
    * Registers a listener to receive events from the playlist tracker.