Keyguard: Enlarge Unlock Pattern on sw320dp-mdpi devices

Slightly enlarge area available for Unlock Pattern by changing margins
and by moving carrier text to emergency call area

Before: http://i.imgur.com/Udr3PTZ.png ( http://i.imgur.com/oShn0so.png )
After: http://i.imgur.com/QUd1bgp.png ( http://i.imgur.com/qKqqKJ0.png )