Merge changes Ia7b7b1d9,I0103856f,I45fa4309,Ib3fab843,Ic171b996, ... into main

* changes:
  floss: consolidate group related members in BluetoothMedia
  floss: allow |leaudio.dual_bidirection_swb.supported|
  floss: propagate VC connection event to audio server
  floss: |set_group_volume| on vc/group connection
  floss: add LEA volume update callback events
  floss: encapsulate cancelled info to |stream_started|