Merge "Add RandomGeneratorFactory test coverage." into main am: 790a6497c1

Original change: https://android-review.googlesource.com/c/platform/libcore/+/2977931

Change-Id: Idb8d7ae1358932451e1a39e4c0b5e274cbd3ea11
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>