Fix issue 2174002: After rejecting Call when device ringtone is mute and...

Fix issue 2174002: After rejecting Call when device ringtone is mute and playing music, audio is not transfered to BT device.

Added a workarouond to request the A2DP output standby directly to audio hardware when the sink is suspended as it seems that the suspend request often fails.

Also take into account resume requests received while a suspend request is pending.