LockscreenShortcutFragment needs onPreferenceTreeClick
- Moved the option to onPrefrenceTreeClick method or the option won't stick and resets itself when we leaves the option screen

Change-Id: Id4f904ba34ab7a8617b4d90f4795fab89f4c4ee5
Add a general preferency in lockscreen interface settings

Change-Id: I401185eea9e8b8249e6e8b2ceccb24682495784a

Conflicts:

	res/xml/lockscreen_interface_settings.xml