audio_amplifier: add hooks for stream parameter manipulation

This allows to modify audio parameters before the first
device selection happens which is necessary when setting ANC parameter 
since it must happen before audio hal hits voice_start_call() and 
selects devices. If setting ANC after stream has been started it will 
trigger a re-selection of devices and cause a short downtime.

Change-Id: Icfddab5ce27235c1567a0557e63b3a7421778187
2 files changed