Lockscreen Notifications: Privacy mode

Hide notifications content on secure lockscreen.

Conflicts:
	res/values-it/slim_strings.xml
	res/values/slim_arrays.xml
	res/values/slim_strings.xml
	res/xml/security_settings_chooser.xml
	res/xml/security_settings_lockscreen.xml
	res/xml/security_settings_password.xml
	res/xml/security_settings_pattern.xml
	res/xml/security_settings_pin.xml
	src/com/android/settings/SecuritySettings.java

Change-Id: Iebe304f48199e4e8f745ee647f266c8caf0aa054