Animate Handle Menu Open & Caption Handle Vanish

Animate the handle menu’s opening. For full screen, the caption handle should expand until it assumes the shape of the top handle menu pill (app info pill). The spec for freeform is not yet specified. As the handle menu opens, the caption handle vanishes.

Test: Manually tested in freeform, splitscreen, and fullscreen modes
Bug: 301494758
Change-Id: I8cc7305813c083a2b2ad6c19a523173162bc021e