Merge "Add null check when settling on LAST_TASK" into sc-v2-dev am: d48fbecd1a

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/16150962

Change-Id: Ib9d50e6c351d0250b70a0f84db9701ad58cbf521