Scan for BLE devices using BluetoothAdapter::startDiscovery as this does not depend on location services on Android. The reasonining behind this is that by not turning LocationServices on there are benefits in terms of privacy as then that information is not available to other applications. It also means it does not drain the battery due to it being turned on.

Therefore if it is possible to depend on the BluetoothAdapter results for BLE if location services is not turned on then it would be good to use that.