Make RecentsView INVISIBLE instead of GONE

This ensures it gets laid out to compute things like page scrolls.

Test: Repro steps to both bugs below
- Force stop launcher, swipe up slightly, hold, and let go to return
  to the current task; ensure no jumps or jank
- Force stop launcher, swipe up and hold to go to Overview, ensure
  no jump on motion pause

Fixes: 180736503
Fixes: 175064755
Change-Id: I44581f87600b02a3c9ddefcb8c94bb3845cd9152