connect_flag always  has zero value and can not be used at all.

It could be even removed from the structure since it is defined only there.  It is dangerous to use use RemoteXY for anything else than toys. Just imagine electric motor remained engaged "forever" even if command link from the smartphone are broken.

Something like this:

void loop()
{
  RemoteXY_Handler ();

  static bool wasConnected = false;
  if ( wasConnected == false )
  {
    if ( RemoteXY.connect_flag == 1 )
    {
      wasConnected = true;
      Serial.println( "Connected..." );
    }
  }
  else if ( RemoteXY.connect_flag == 0 )
  {
    wasConnected = false;
    Serial.println( "Connection lost, rebooting..." );
    rebootArduino();
  }
}

I am a beginner and I don't understand how to use 'connect_flag'.
Can you please explain me in more detail.

I need a code to reboot Arduino when the connection between HC-05(06) Bluetooth module and android is lost.