Revert "Revert "[1/2] Base: Lockscreen blur""

This reverts commit cabbbcd5621021d14b0e8b6d6234e6c96545fdc7.
Revert "Frameworks: Lockscreen custom wallpaper (1/2)"

This reverts commit e72cbc66be4ed9e801c429e52898bee50aaa2beb.