Merge "[2/n] Let picker refresh preview when user selects a different grid"...

Merge "[2/n] Let picker refresh preview when user selects a different grid" into udc-qpr-dev am: 49493200

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/24344634



Change-Id: Ic643508ab04672134d06064773b0fe6cf71a65a9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>