Merge "Wait for taskbar to become visible after closing launcher in tests"...

Merge "Wait for taskbar to become visible after closing launcher in tests" into sc-v2-dev am: 17e9b51e

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15301470

Change-Id: Iec444f448028917ae26f993f08508e3b89ac71a6