[2/2] Settings: Lockscreen Notifications

PS6:
    [2/2] Lockscreen Notifications: make offset top user configurable & add privacy mode

PS7:
    Fix Derp
PS8:
    Rebased

PS10:
    Restore PS8

Change-Id: Ic66c0ff9d36bc390f5a434559468fe3752faf285

Conflicts:
	res/values/custom_strings.xml
	res/xml/security_settings_lockscreen.xml
	res/xml/security_settings_pin.xml