Merge "MusicFx: add a KeepAliveService to allow client app to bind" into main am: b34fac6fb9 am: 41bdc4ce5f

Original change: https://android-review.googlesource.com/c/platform/packages/apps/MusicFX/+/2736934

Change-Id: I2fffe7eb486fdb4a7967b459e78930bdf692e9c4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>