Bug: b/307278302

Fix clipping of DesktopTaskView border on focus/ hover

Hover border: https://screenshot.googleplex.com/B9CUW49q6inMW75
Focus border: https://screenshot.googleplex.com/36uLJ4jC295t7PZ

`android:clipToOutline` prevents drawing outside view bounds and results in the focus/ hover border getting clipped, instead we can use `android:clipToPadding` with a small non-zero padding to clip children and allow drawing a border outside the bounds

Change-Id: I7e763f7ee8c7fd1090c7778c2c000d2b792bef06