BT_Audio: Updated Check for TWS+ switch

- Race condition between disconnection of first earbud and
  connection of second earbud, the configuration of second
  earbud is ignored because it is considered a case of TWS
  switch.
- Since MM Audio removes the disconnected device from list
  after delay of ~600ms, this creates a window where a new
  connection goes unprocessed when it happens immediately
  after disconnection.
- This change fetches real time connection state from A2DP
  to overcome the race condition.

CRs-Fixed: 2606382

Change-Id: I2df8447acb1d8e1b843a49906f2f3e3993cce5d6