Fix bug in Timeline.getRemovedAdGroupCount()

#minor-release

PiperOrigin-RevId: 389174519

library/common/src/main/java/com/google/android/exoplayer2/Timeline.java

@@ -710,7 +710,7 @@ public abstract class Timeline implements Bundleable {
      * 0} (inclusive) and {@code removedAdGroupCount} (exclusive) will be empty.
      * 0} (inclusive) and {@code removedAdGroupCount} (exclusive) will be empty.
      */
      */
     public int getRemovedAdGroupCount() {
     public int getRemovedAdGroupCount() {
-      return adPlaybackState.adGroupCount;
+      return adPlaybackState.removedAdGroupCount;
     }
     }
 
 
     /**
     /**