Temporarily disable art-tests for userfaultfd GC am: a8760e2839

Original change: https://android-review.googlesource.com/c/platform/art/+/2191948

Change-Id: Ic193e8ee99ef3fc26b36191255d303d8290066c8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>