Revert "Exclude empty and custom screens when centering wallpaper"

This reverts commit f7bef2545ba45e8405dd5a00c0d276d669bf0ad0.

Change-Id: Iee25ecd12eb5b7be9f14959336af6c6c49d88c25
(cherry picked from commit 11827406fcd38de7f4acbb7093de48c09a092142)
Revert "Center wallpaper when only one screen"

This reverts commit eacfd7fd535b4510cc43400c145c46db10110d08.

Change-Id: I39677c5d0f61ba66297a39f5e88b96f59a0df46a