Merge "audio: fix race when stopping a stream" into sc-dev am: 84165ed1 am:...

Merge "audio: fix race when stopping a stream" into sc-dev am: 84165ed1 am: 33a7d424 am: 9b63586e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/15115530

Change-Id: Ifca5c0da39c7948e6f2ec6e8483a168faaedfeba