Support aaudio channel mask.

This CL includes:
1. Add channel mask enums.
2. Add an API for setting channel mask in aaudio.
3. Add an API to query channel mask.

Test: atest AAudioTests
Bug: 192597880
Change-Id: Id0792780cc056285b2da403770889078857222d8
diff --git a/services/oboeservice/AAudioServiceEndpointShared.cpp b/services/oboeservice/AAudioServiceEndpointShared.cpp
index 0d453cf..3143f18 100644
--- a/services/oboeservice/AAudioServiceEndpointShared.cpp
+++ b/services/oboeservice/AAudioServiceEndpointShared.cpp
@@ -78,7 +78,7 @@
     result = mStreamInternal->open(builder);
 
     setSampleRate(mStreamInternal->getSampleRate());
-    setSamplesPerFrame(mStreamInternal->getSamplesPerFrame());
+    setChannelMask(mStreamInternal->getChannelMask());
     setDeviceId(mStreamInternal->getDeviceId());
     setSessionId(mStreamInternal->getSessionId());
     setFormat(AUDIO_FORMAT_PCM_FLOAT); // force for mixer