A2dpSink: Initite Handoff when device is got connected.

Parial change(#143011) of Q already taken care as part of
change #164469 in P. Other partial change is taken care
through this change.

- Initite Handoff when device is got connected, instead doing
  on Audio config change.

- Remove toast message displaying.

CRs-Fixed: 2442486
Change-Id: Ia21cef9f8d0839698d595e8390979392cfc36994
1 file changed