audio: Update default audio implementation.

Allow the default audio implementation to use the sample rate and
format provided by the application, but default to 16-bit stereo
for both input and output.

Also, default to 10ms output buffer and 20ms input buffer.

Bug: 70692394
Test: Audio device and output stream created successfully with
      the default frame_count.
      Audio device reports 20ms for input buffer size.
      Audio input stream created successfully with defaults.
      Setup device with audio_policy_configuration_stub.xml;
          no failures for GTS tests: GtsGmscoreHostTestCases
          -t 'com.google.android.gts.audio.AudioHostTest'
Change-Id: If496fc89f72f26266a7ed9b59acf88d1ca76e704
1 file changed