Do not update queue when the queue did not actually change to avoid

unnecessary updates are broadcasted to all clients.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=162728670

extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/TimelineQueueNavigator.java

@@ -93,7 +93,12 @@ public abstract class TimelineQueueNavigator implements MediaSessionConnector.Qu
 
   @Override
   public void onCurrentWindowIndexChanged(Player player) {
-    publishFloatingQueueWindow(player);
+    if (activeQueueItemId == MediaSessionCompat.QueueItem.UNKNOWN_ID
+        || player.getCurrentTimeline().getWindowCount() > maxQueueSize) {
+      publishFloatingQueueWindow(player);
+    } else if (!player.getCurrentTimeline().isEmpty()) {
+      activeQueueItemId = player.getCurrentWindowIndex();
+    }
   }
 
   @Override