CP of go/ag/16674532
1. Enable AudioProxy service and client library.
2. AudioProxy service will implement the audio HAL, so add the audio
policy config file.
3. AudioProxy also has its own AIDL interface. Add the compatibility
matrix file for the new AIDL interface, and the audio HAL.
Bug: 197547824
Test: Build and local run
Change-Id: I9aa3dbced63f071bebade5de7d996655fe502295
