Updated system app
Fixed - task 437: [bug] settings / resetting screen time counters shouls
happen in the service writing the boor ref and not in the handler 
https://github.com/asksven/BetterBatteryStats/issues/issue/437
Fixed overflow problem for long timespans between reboots:
https://github.com/asksven/BetterBatteryStats/pull/412/files
Fixed - task 440: [feature] better support of root 
https://github.com/asksven/BetterBatteryStats/issues/issue/440
Fixed - task 441: [feature] offer to install system app on 4.4+ 
https://github.com/asksven/BetterBatteryStats/issues/issue/441
Fixed - task 439: [bug] dumpfile chapters should reflect the fact that
more sections require root on 4.2.2 
https://github.com/asksven/BetterBatteryStats/issues/issue/439
Fixed - task 435: [bug] on kitkat accessing appops from package view
causes an FC 
https://github.com/asksven/BetterBatteryStats/issues/issue/435
Refactored seralize/deserialize (plain objects): moved to Reference as
the class should take care of marshalling/unmarshalling itself

Added gson marshalling/unmarshalling as alternate an more manageable
persistence method
Fixed - task 429: [feature] replace pojo serialization to db with json 
https://github.com/asksven/BetterBatteryStats/issues/issue/429