Merge "Uses WorkspaceSurfaceHolderCallback for GridPreviewer" into ub-launcher3-master am: 0f5fb7e610 am: 23b2f1251f

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/WallpaperPicker2/+/11751402

Change-Id: Ib6d89737afac01a353c7ba2a51cdd0ca9fc3d6ae