hal: restore a2dp device for active usecases when out of suspended

Routing request to a2dp could come before a2dp out of suspended
thus the request is ignored, and audio continues on the last device.

Restore device to a2dp for all current active usecases if a2dp is
requsted before.

CRs-Fixed: 2063836
Change-Id: I43a9f65315dcf0ccd19cf30485c3093ec47853ca