[2/3] 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