audio: Implement GetAudioConfig for HAL 2.1 am: 0b12cea833 am: b7e7872798 am: 68facba64f

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1608076

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I771b93be0d08b4d0eb1352dc19958b5a2b4ca5f1