How do I add native Android code to Gluon Mobile framework? - Bluetooth Low Energy

Question

I'm going to implement Bluetooth Low Energy onto a Android mobile application made by Gluon framework. To do that I need to use Android native code inside my Gluon project.

I have follow this manual GoNative how to implement native Android into my Gluon project code without success.

My issue is that I cannot import the android.util.Log library.

package com.gluonhq.charm.down.plugins.android;

import android.util.Log; // <-- The import android cannot be resolved
import com.gluonhq.charm.down.plugins.LogService;

public class AndroidLogService implements LogService {

    private final static String TAG = AndroidLogService.class.getSimpleName();

    @Override
    public void log(String message) {
        Log.v(TAG, message);
    }
}

My goal is to have communication with other devices. I'm not talking about GATT services. I'm talking about sending and receiving data such as bytes.

private OutputStream outputStream;
private InputStream inStream;

private void init() throws IOException {
    BluetoothAdapter blueAdapter = BluetoothAdapter.getDefaultAdapter();
    if (blueAdapter != null) {
        if (blueAdapter.isEnabled()) {
            Set<BluetoothDevice> bondedDevices = blueAdapter.getBondedDevices();

            if(bondedDevices.size() > 0) {
                Object[] devices = (Object []) bondedDevices.toArray();
                BluetoothDevice device = (BluetoothDevice) devices[position];
                ParcelUuid[] uuids = device.getUuids();
                BluetoothSocket socket = device.createRfcommSocketToServiceRecord(uuids[0].getUuid());
                socket.connect();
                outputStream = socket.getOutputStream();
                inStream = socket.getInputStream();
            }

            Log.e("error", "No appropriate paired devices.");
        } else {
            Log.e("error", "Bluetooth is disabled.");
        }
    }
}

public void write(String s) throws IOException {
    outputStream.write(s.getBytes());
}

public void run() {
    final int BUFFER_SIZE = 1024;
    byte[] buffer = new byte[BUFFER_SIZE];
    int bytes = 0;
    int b = BUFFER_SIZE;

    while (true) {
        try {
            bytes = inStream.read(buffer, bytes, BUFFER_SIZE - bytes);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Code source

Here I open the GoNative example from Guon's Github.