Atom: Add BluetoothSocketConnectionStateChanged

* Logs when a Bluetooth socket's connection state is changed
* A Bluetooth socket can be:
  - RFCOMM socket
  - SCO socket
  - BR/EDR L2CAP socket
  - BLE L2CAP socket

Bug: 112969790
Test: make, test drive with statsd
Change-Id: I97b1e650e197a0dad1e2959e2f5b4dd98370d892
Merged-In: I97b1e650e197a0dad1e2959e2f5b4dd98370d892
(cherry picked from commit 815cdbaa)