Revert "Remove lag when launching an app"

This reverts commit 8d0b074518c45562bcb2db67021a5b398de7d8cc.
remove some lag launching apps and improve scrolling

Change-Id: Ib10c11a1a3a798e57ddd31f550461b9ebd17bc38

Conflicts:
	core/java/android/widget/AbsListView.java