audio: allow standby for direct track

Delay standby for offload track use case is not suitable for direct
track in PCM format, because player torn down doesn't necessarily happen.

To avoid AP looping infinitely, allow standby right after direct track
in PCM format is paused.

CRs-Fixed: 986784
Change-Id: Id0026ac9891a12acc4affa446b2bc841559fcc28