Merge "AudioService: fix volumegroup mute sync" into tm-qpr-dev am: ac7514038f am: d4410e0d6e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21223480

Change-Id: Ia3d5c82072060ee96f6a2797ffbe044bcc22abc1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>