AudioService: test mic muting API behavior with errors

 Implement unit test for AudioService's mic muting API.
 This requires being able to inject existing
AudioSystemAdapter in AudioService class, and creating an adapter
for operations that require running in system_server.

Bug: 153103117
Test: atest AudioServiceTest
Change-Id: I92538f585c5567718a4bad5666b2efafd446f4d3