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: Iea88e6b232d10ec5d3a561b50ac20fea2632d436