Merge "Prevent Taskbar from stashing in immersive mode overview." into tm-qpr-dev am: 0355c793c0

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/21560134

Change-Id: I75a8b22ad44b3ccf78a546f7d7569be9fc1dbff2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>