Do not bypass wallpaper visibility update during keyguard going away.

Reason for cherry-pick: Remove `waitingToShow`, which was causing issues when the wallpaper was being discarded from a transition. Remove redundant logic to include wallpaper in unlocking transition. 

Fix: 296909507
Test: WallpaperManagerTest
Test: Manual, unlock from AOD

Change-Id: I373760932de76ea89b890e64fbd97fa43600103c
(cherry picked from commit 9a566e3c)