Switch to active BT route when changing focus

Send a BT_AUDIO_CONNECTED message right away if we try to connect to BT
audio and we find that it's already connected. This way we don't get
stuck in a quiescent state.

Change-Id: Idbfb4b77a243d300d47703643e22d5f1d8a2474c
Fixes: 79501344
Test: added a unit test.
6 files changed