Move robolectric tests from 3.6.2 to 4.8.2 am: 709b39831d

Original change: https://android-review.googlesource.com/c/platform/packages/apps/WallpaperPicker2/+/2292133

Change-Id: Icbd6f6cae5bbcc26489bfc80a7ef22a52e5bcb5f
Signed-off-by: Automerger Merge Worker <[email protected]>