Change layout anim from Animation => Animator

Change the layout animation to use animators instead of the built-in
animation-based layout animation. Animator-based animations are more
flexible and can act on the view properties themselves, making it
easier to deal with if we need to cancel the animation later from a
conflicting animation (i.e. we find out we need to animate a view
out).

Bug: 114136250
Test: Go to recents, see items animate in
Change-Id: Id8227cd50e81999cac98912ac58cd2d6864c40af