Revert "Disabled the wallpaper when completely in -1 Now space."

This reverts commit f3a8e8c0bd.

Bug: 12978354
Change-Id: I11f1eeaab4fad9a2e4acf835144f0b0dc6fac54b

src/com/android/launcher3/Launcher.java

@@ -2887,7 +2887,7 @@ public class Launcher extends Activity
                 mWorkspaceBackgroundDrawable : null);
     }
 
-    protected void changeWallpaperVisiblity(boolean visible) {
+    void updateWallpaperVisibility(boolean visible) {
         int wpflags = visible ? WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER : 0;
         int curflags = getWindow().getAttributes().flags
                 & WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER;