Settings: correct wallpaper custom image size to new keyguard size

due that custom images no reflect the content as well behind the
statusbar we do not need to take it into account anymore
when we start cropping to do not get streched image view
on the keyguard

Change-Id: Iae8fd4de3db63e0dead1ffc07ac4950c88824977
Merge "Settings: correct wallpaper custom image size to new keyguard size" into jb4.3