Merge "Release AudioTrackCallback when the track is removed." into rvc-qpr-dev am: c7d12948 am: 5f324d7a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/12629238

Change-Id: I6dfb59d036e2c540cbe326f57c83829a46463b9b