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

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I79b053ce7b0d4c2969ef63b2b0af635a959907d3