Merge "Stub implementation for USB audio HAL." am: 2f97fbccb8

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2397735

Change-Id: Idb73c777d89cbf985d45440ee19667ca2f9a85d7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>