Add implementation of homepage swipe to dismiss.

- Only enable swipe for slice full/half card.
- Add isPendingDismiss in ContextualCard to determine if we should show
dismissal view.
- Take out long press feature.

Bug: 126214056
Test: robotests
Change-Id: Ib03e605347b2f50d3c62fcd4f95875a21cc9ef1c