Merge "Add new quickstep test for many tasks open at once." into sc-v2-dev am: 3c647ff30a am: 2e5511ad4b

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15992810

Change-Id: I368651cbc9255f50baf3e741b561bebb16b18dd2