Activate HFP and A2DP at the same time

When BT classic is connected there is time gap between HFP
connection and A2DP connection. So if BT classic is connected
while LE audio is in use, there are some change the audio comes
from phone speaker for a while.
This CL fixes that issue by activating both HFP and A2DP
at the same time.

Bug: 247453067
Test: atest BluetoothInstrumentationTests:ActiveDeviceManagerTest
Change-Id: Ie1ab1582732b4faa7b29b9f2f6dd543b4ba96a51