Add the ability to record directly to the local Android device

[GrazianoCapelli]

It is not Always needed (nor useful) to record to the remote SD at a high frequency;
Sometimes the user could only need to record the displayed data (at low rate, like 2 - 5 Hz).
I imagine a biker with the android device on the handlebars, for example.
In this case a local recording would be very useful.

PROS:

• A SDCard is not needed in the remote device
• Significantly smaller log files
• It is not necessary to download the recorded file from the remote SD

CONS:

• Low frequency rate (the limit is the BT baud rate and the $DTA string length)
• The recording is stopped when the ADC is disconnected to the Android device