title: BLE onConnectionStateChange called twice when closing a connection
body: <p>Finally got my device (based on TI's CC2541) to work with my phone (a prototype/non-commercial-yet phone running Android 4.3). I can scan, discover, connect and get notifications successfully. However, when I disconnect (calling BluetoothGatt.disconnect()), the onConnectionStateChange callback is called with newState=STATE_DISCONNECTED (as expected) but then immediately called again with newState=STATE_CONNECTED. <br>
  The connection is definitely terminated so I'm not sure why I'm getting the 2nd onConnectionStateChange call. Has anyone experienced anything similar?</p>