Merge "stagefright: notify async release complete" into rvc-dev am: 3244d0db...

Merge "stagefright: notify async release complete" into rvc-dev am: 3244d0db am: cb2a9094 am: c563de4c am: 7c5c1dad

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/11795217

Change-Id: I2332a4073495e32d9a32ee1d78a7b5cbfdea4675