A2DP: Notify soft handoff triggered status to audio manager

-BT stack call back A2DP SM to notify when soft handoff is triggered.
A2DP SM will notify the audio manger to reconfigure the encoder
session in DSP.
-Read offload codec capabilities support property to initialize
split a2dp configuration.Disable multicast in split a2dp mode

Change-Id: I8872dda28205e3065cd0aef9d0a9f43804f4fb83