Remove visibility and show race condition.

Visibility and show were emitted by two different flows. Sometimes we
were setting visibility to visible before show is called, leading to UI
jank. I removed the visibility flow and added it into the show and hide
flows. I also removed the hide flow for further simplification.

Fixes: 263924084
Bug: 267821080
Test: Long press lock icon to show bouncer like 20 times.
Test: Look at sim pin and sim puk views.
Change-Id: Id5d0e86eb64844b06f6082e2c51c5a3e50c45a41