need to think of how to integrate MiBandActivitySample and PebbleActivitySample
into the app. There's GBActivitySample, MiBandSampleProvider, PebbleSampleProvider,
etc.
This avoids a lot of problems because java
- does not know unsigned values
- jvm and dalvic do not internally support byte and short
- sqlite does not know them either
Currently we get the heart rate when synchronizing activity data
(i.e. not live) and we write it to the activity database so that we
can show a nice graph. The value is currently always 0 though,
because we can't enable recording hr, yet.
