Merge "audio: Add methods for controlling hw volume" am: 0ae5167223 am: e47751040d

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2255291

Change-Id: I9d7aa112a0b9f30fb0c48ffde2a198e6631658a3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>