Merge "Add shadow for theme preview workspace texts" into ub-launcher3-master...

Merge "Add shadow for theme preview workspace texts" into ub-launcher3-master am: 7ff9110f am: 5be0648f

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/11617270

Change-Id: I825c4d118eed0148f8959834d976bfc62ed09d45