Fade out minimized view before animating expanded view

Currently, we essentially replace the minimized view in-place,
setting one view to GONE and the other to VISIBLE instantaneously.
This looks jarring; add an animation to quickly fade out the old
minimized view before running the normal entrance animation on the
expanded view.

Bug: 260707686
Test: manual (visual change)
Change-Id: Ib4213a3927533b2ed35f79823f798c2485cce28e