Add chrome.bluetooth and chrome.bluetoothLowEnergy for android

I don't think this API (`bluetoothManager.getConnectedDevice(int profile)`) works with BluetoothSocket's profile from its [documentation](https://developer.android.com/reference/android/bluetooth/BluetoothManager.html#getConnectedDevices(int)). `GATT_SERVER` and `GATT` are the only two acceptable profiles for `getConnectedDevices`.

For `BluetoothSocket`, we can implement a `BluetoothProfile.ServiceListener` or Add `BluetoothDevice.ACTION_ACL_CONNECTED` to the broadcast receiver of `BluetoothAdapter` to monitor the connection state of a bluetooth socket. I didn't implement that because we currently don't support `BluetoothSocket`, and it will require another type of bluetooth scan when we want to support that.