Fix: wallpaper changes when changing lockscreen WP

Since LockscreenWallpaperPickerActivity did not override
cropImageAndSetWallpaper the homescreen wallpaper was changing
when selecting the default_wallpaper resource.

Change-Id: I26dd28e628a3ef701ad92a81aa80327d3ccba092
Merge pull request #10 from CyanogenMod/cm-11.0

Fix: wallpaper changes when changing lockscreen WP