AudioService: fix BT SCO audio reconnect

Fix regression in commit 6ac41ac3 preventing SCO audio automatic reconnection
when an HFP device is connected and a communication route client exist with an
active route to this device.
The commit made the communication device check synchronous which broke
the active Bluetooth device check in BtHelper.

Bug: 436347080
Test: repro steps in the bug
Flag: EXEMPT bug fix
Change-Id: Ie5901420ac42953567b5279b7fbc975cc78e8295