Merge "Adds Dark mode support to Sandbox." into ub-launcher3-rvc-dev am: 55a758253b

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/11720146

Change-Id: Ib78c370eda25c377342a7ac4ee0d5e1def2fdced