Settings: MediaScanner behavior on boot (3/3)

credits to corcoran, Slimroms

Change-Id: Ie380c12eace6bc743bebb3058d5248f06521a485
Use java.util.Objects instead of internal API

Change-Id: Ib0d797b3e7f2e4f831f52832776b64c0973880b3
Settings: follow kitkat's ui

- manage apps; tab selector and ram usage
- battery data usage bar
- app widget toggle

Change-Id: I804b4b47563545d7ab124f4cc4800ef4034bf754