Fix background animator not resetting

Test: Set wallpaper, make sure screen is not black.
Change-Id: I4031375e0892906a4e4085ce05664191a55bfb4e
Fixes: 32375010

services/core/java/com/android/server/wm/DisplayContent.java

@@ -2256,6 +2256,8 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo
     }
 
     void updateWallpaperForAnimator(WindowAnimator animator) {
+        resetAnimationBackgroundAnimator();
+
         final WindowList windows = mWindows;
         WindowState detachedWallpaper = null;