Fix for BluetoothGattCallback.onConnectionStateChange being called more than once

This patch fixes the issue, where the onConenctionStateCallback is being
called twice when device is connected. This happens only if device was
connected before, and the physical connection was kept alive.

This issue was introduced during white list refactor.

Test: GattConnectTest:test_gatt_connect_in_quick_succession
Bug: 117182283
Merged-In: Id94db9429e31224ef35eb2c99c0f9a65e7c27d32
Change-Id: Id94db9429e31224ef35eb2c99c0f9a65e7c27d32