Lazily instantiate LauncherAppState.

The application context for LauncherAppState is supplied by
the application whenever it starts; don't ask for an
instance before that.

Change-Id: I1ca8ea04238a357a682f79250f08813ead7ae532

src/com/android/launcher3/PagedViewCellLayoutChildren.java

@@ -91,7 +91,8 @@ public class PagedViewCellLayoutChildren extends ViewGroup {
             View child = getChildAt(i);
             PagedViewCellLayout.LayoutParams lp =
                 (PagedViewCellLayout.LayoutParams) child.getLayoutParams();
-            lp.setup(mCellWidth, mCellHeight, mWidthGap, mHeightGap,
+            lp.setup(getContext(),
+                    mCellWidth, mCellHeight, mWidthGap, mHeightGap,
                     getPaddingLeft(),
                     getPaddingTop());