Remapping coordinate system in Android app

I'm implementing a simple Android app, in which I need to identify the north.

So I've implemented SensorEventListener and I used something like this:

@Override
public void onSensorChanged(SensorEvent event) {
    if(event.sensor.getType() == Sensor.TYPE_ROTATION_VECTOR)
    {
        SensorManager.getRotationMatrixFromVector(mRotationMatrix, event.values);
        SensorManager.remapCoordinateSystem(mRotationMatrix, SensorManager.AXIS_X, SensorManager.AXIS_Z, orientationVals);
        SensorManager.getOrientation(mRotationMatrix, orientationVals);

        orientationVals[0] = (float) Math.toDegrees(orientationVals[0]);
        orientationVals[1] = (float) Math.toDegrees(orientationVals[1]);
        orientationVals[2] = (float) Math.toDegrees(orientationVals[2]);

        tv.setText(" Yaw: "+ orientationVals[0] +"\n Pitch: "+ orientationVals[1]+"\n Roll: "+ orientationVals[2]);
    }

}

The problem is that the code line

SensorManager.remapCoordinateSystem(mRotationMatrix, SensorManager.AXIS_X, SensorManager.AXIS_Z, orientationVals);

seems to not work, since in both case (with or without this code line) the value of Yaw (azimuth) depends on the orientation of the head of the phone (letting it layied on the back side)

what I expected, using my remapping, was that the Yaw changed based on the orientation of the back of the phone (the rear camera).

Why my remapping does not work?