libaudiohal@aidl: Implement microphone info retrieval

Implement DeviceHalAidl::getMicrophones and
StreamInHalAidl::getActiveMicrophones.

Bug: 205884982
Test: atest android.media.audio.cts.AudioRecordTest
Test: atest android.media.audio.cts.AudioManagerTest
(both w/AIDL enabled)

Change-Id: I4f07cd9b2273ab93d9d0cda1349a50730c30b528
4 files changed