We should keep consistent split rule for wallpaper and other home menu item. So, we create this cl to register the split rule for wallpaper. Also, I do some minor refactoring in this cl for reusing existing method and better code quality. Test: Go to wallpaper, and click back key. App can close. Fix: 204406425 Fix: 204364572 Change-Id: Ia7de9483b351d1121cc26c4af1cb8a89ad0a16bc