AudioService: more communication mode fix

Do not reset communication mode when an app is not playing or
capturing audio if the app is not the audio mode owner.
In case of dual call situation, a VoIP call can be placed on hold and it
is legit for the app to remain in the mode owner stack but pause
capture and playback.

Bug: 161564483
Test: VoIP call interrupted by Cell call.
Change-Id: Iac5bee9b606e3663b63a4c1c58f9c7a880ab0311