Settings: Security: implement a pin keypad shuffler [2/2]

Credits to cristianomatos for implementing this feature on PA...

this is to further prevent people using the tablet guessing your pin based on fingerprints left on the screen
example of the expected outcome - https://www.dropbox.com/sh/r3xb2q53ksaqni9/Oz1Eu8Dm7O

PatchSet:
- fix checkbox was wrong assigned
- enable only for PIN Password lock
- small cleanup of old code

PatchSet:
- cleanup

PatchSet:
- add modes.....disabled/always/on request

THIS COMMIT ALSO INCLUDE LOCKSCREEN SETTINGS INTO LOCKSCREEN TAB IN SETTINGS

Change-Id: I7e485827f6d62ee239015cfa96f2a20169d28486

Conflicts:
	res/values/cr_arrays.xml
	res/values/cr_strings.xml