Reload wallpaper after user unlock.

Live wallpaper may not support direct-boot aware, however, those kind of wallpapers should be showed after user unlock.
It may not suit to call switchUser after onUnlockUser since there is no user switch happen.

Bug: 78539162
Test: Manual test, reboot and switch users.
Change-Id: I99f8ad99c913ac05bc51c38c3da5aa51c0ba98fd