Create some basic check when pslab board does not respond

[froscon2024]

https://github.com/fossasia/pslab-python is reporting correctly a error that the pslab device does not respond and that why its reported as not detected.
The android app fails this basic test. When you install the ESP firmware on v6 hardware, it does not respond over serial any more. The python tool correctly reports that. The android app instead is missing this check. I had to spend much time trying to understand what is wrong and why nothing is working.
Such basic check should be implemented also in the android app.