Framework: Add Advanced reboot [1/2]

This commit responds to a setting in Development settings for including
options in the power menu for rebooting into recovery and bootloader.

It has three settings:
- Disabled [Default]
- Enable when unlocked
- Always show

Enhanced by : kufikugel

PS 2-3 : Add advanced features
PS 5   : Cleanup

Change-Id: Ie130e398aa55857509fddcc49a846cd0390c33e8

Conflicts:
	core/res/res/values/slim_symbols.xml