Fix A2DP device is not made active when connected

The issue is happening when we disconnect and connect the device again.
On the next connection ACTION_ACTIVE_DEVICE_CHANGED and
ACTION_CONNECTION_STATE_CHANGED can be delivered in order.
If ACTION_ACTIVE_DEVICE_CHANGED happens before then mBluetoothRoutes
does not have a valid BT route which result in UMO issues.

We handle this scenario for hearing aidand LE devices but not for A2DP
devices. This CL changes the handling of A2DP devices similar to what
we have for other profiles.

Test: tested manually (see more details in the bug)
Bug: b/299268431
Change-Id: I432f9413b0b46a7c92a1061f94d88a3700fd82dd