Merge "Reduce margin for DropTargetBar to avoid buttons to be truncated." into sc-dev am: eefccccb19

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15155531

Change-Id: I92c997fbd0d0f47e78e5169e8cad9938bd2af0a0