Make All Apps<-->Workspace transition smoother

- grouping workspace/all apps anims into one
animator set, prevents blip when one of them ends
early and its end anim handler does lots of work
mid-animation
- updating pivots for all apps zoom if layout
changes
- avoid running unnecessary animations on
workspace pages
- prevent unnecessary reloading of pages in
All Apps

Change-Id: I53a75f7c4c7d254057e2f8f4fd17711e8862256d

src/com/android/launcher2/PagedViewGridLayout.java

@@ -109,6 +109,7 @@ public class PagedViewGridLayout extends GridLayout implements Page {
     @Override
     public void removeAllViewsOnPage() {
         removeAllViews();
+        mOnLayoutListener = null;
         destroyHardwareLayer();
     }