ModLowBatteryWarning: fix null pointer exception in setFlashing hook
ModDisplay: module for display tweaks
- set minimum brightness applicable to manual brightness setting
- set autobrightness levels
- implemented custom Autobrightness Dialog Preference with special
strategy to obtain default values from the system. When preference
is open for the first time there is no user config stored yet.
A broadcast will be sent with intent to be caught by ModDisplay running
in system context which will read system autobrightness config and
send results back to GravityBox app running in user context 
using ResultReceiver - to set initial system specific autobrightness
levels.