audio: new parameter key for HW A/V sync ID allocation

The HW A/V sync ID is retrieved from the HAL by calling
global get_parameters() with key AUDIO_PARAMETER_HW_AV_SYNC.

After the output stream is opened, the HW A/V sync ID is communicated
by stream set_parameters() with key AUDIO_PARAMETER_STREAM_HW_AV_SYNC.

Bug: 17112525.
Change-Id: Id1e3a3aa1e88d15461a609b381ca8c1902735a29
1 file changed