aaudio example: loop and add noise blip at start

Loop while starting and stopping or pausing/flushing.
Check framesWritten - framesRead.

Blip so we can tell if the beginning of the sound was cut off.
Add -t option for the high pitched prefix tone.

Test: this is a test
Change-Id: I2a642be67f4e80caad015254d006a0153b46e3f7