Move the PreviewItem drawing/animation logic to PreviewItemManager.

We want this refactor in O-DR since we will be adding more animations:
- closing from a non-first page (ag/2455887 b/36022592)
- new on-drop animations *if we end up removing the permutation logic.

Bug: 36022592
Change-Id: I82b8f5f5033d4fd9bd50fbe414b0fb721891d043