Merge "Add SplittableRandom test coverage." into main am: 15ad3bc9fa am: 55a2ef83fc

Original change: https://android-review.googlesource.com/c/platform/libcore/+/2977254

Change-Id: I28275ee3baa0aab14a677bf7e5589941bf6ed9bf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>