Load and store user configuration for do not disturb. Separate
out service-related aspects into new helper. Make config availble
over NoMan for settings.
Implement phone + message based filtering (package whitelist for now).
Implement automatic enter/exit zen mode overnight scheduler.
Bug:14211946
Change-Id: Ib28aab0e4c5c9a5fd0b950b2884b1ab618fdfeca