Due to the variable delays in the system, the recording sound can still be heard
if the audio track is started early. This happens even after we suppress a relative
long period of initial audio for a recording session. By starting the video track
before the audio track, we effectively play the recording sound earlier.
bug - 3371141
Change-Id: I2cccf77eae953d96827fc080c618b1d962445c26
44b004b0c2