Add volume control for AOSP USB audio HAL. am: 016fa2107c

Original change: https://android-review.googlesource.com/c/platform/hardware/libhardware/+/2419939

Change-Id: I3afef6641d042b8e2b06602462101c4adea715a0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>