screenrecord: Add audio support

Adds audio recording to the screenrecord system. Note that
while recording, the audio is muted from the device output,
and that the audio volume is controlled separately (so make
sure to turn up your volume if you hear nothing).
Audio from the microphone can also be recorded by adding
--microphone to the command line.

Change-Id: I97dfcaf3d93b786c5466e1f4215549e3d015bcf0
[2/4] av: Audio Themes Support

On the Java side, Android has support for both a
Video Record Start sound, and a different Video
Record Stop sound. However, this part here only
supports one video recording sound.
We added support for RECORDING_STOP sound (by default,
the same as RECORDING).

Change-Id: Iaebddd8ebf8b21633e802589a4a6175492df8f29

Conflicts:

	services/camera/libcameraservice/CameraService.cpp
Screenrecord: allow force mic for audio

Some older devices audio blobs do not support audio submix,
allow those devices to force using the mic for audio while
screenrecording.

Change-Id: Ief3a14e00d0bf32cc131742fb82556621f54be36