Restore jankless transition keyguard-to-wallpaper

There is still a flash of black when going to a non-wallpaper activity
from keyguard. This is not a regression from jb-mr2 and any fixes to
clean it up are too risky at this late date.

Fixes (partially) bug 11570753.

Change-Id: I17aaae4ab8be570f7e28276a7b8ac4b8685e7551

services/java/com/android/server/wm/WindowManagerService.java

@@ -8525,7 +8525,6 @@ public class WindowManagerService extends IWindowManager.Stub
                 // We are transitioning from an activity with
                 // a wallpaper to one without.
                 transit = AppTransition.TRANSIT_WALLPAPER_CLOSE;
-                mAnimateWallpaperWithTarget = true;
                 if (DEBUG_APP_TRANSITIONS) Slog.v(TAG,
                         "New transit away from wallpaper: " + transit);
             } else if (mWallpaperTarget != null && mWallpaperTarget.isVisibleLw()) {