Implement PA's Lockscreen ShortCut

Change-Id: Ia61e71e4a36f7f41a9e8763338f5eab28c3e9671
Lockscreen: enable longpress on expand challenge handle (2/2)

If enabled it will be possible to longpress the little lock icon.

If it is an unsecure screen lock then the longpress will unlock the device.
If it is secure then the widget will fade into the background and you need
to enter the pattern, pin, password or whatever.

Change-Id: I543a8a5a6f643f7dd4561700aeb191448626db2f
PS2: better description - thx Nitroz