Update HardwareListActivity.java

At first, this code is based on BlueFlyVario v0.61b.
I cannot get current HW setting value from BlueFlyVario.
So, I used file saving & reading.

<Optional Tip>
In this original code, I don't know where user mainactivity get a pressure. Anyway, If you use a handler method, it is not good.
Handler method cannot assure fast sampling time.
So, I recommend that thread loop should be used in getting value of pressure.