Merge "audio: Add methods for controlling hw volume" am: 0ae51672 am: e4775104 am: f6d3ea6c

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



Change-Id: I78e4045cdef80548f62dc76c794ff43ecff91488
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>