audio policy: workaround for truncated touch sounds

Implement workaround to avoid touch sound truncation when
audio path or volume changes are triggered by user actions.

Also:
- Fix regression introduced by commit c75307b7 causing failure
to honor playback start delay in case of path change.
- Fix failure to report path switch delay in updateCallRouting().
- Make sure we delay temporary mute according to requested device
switch delay in checkDeviceMuteStrategies().

Bug: 29528161
Bug: 27535199
Change-Id: Id729579b6623ee67a767055b9aca7d2e2dde8491