Initialize userfaultfd availability even when not using it am: 6c6e2df516

Original change: https://android-review.googlesource.com/c/platform/art/+/2402134

Change-Id: I6e7953f410b737e5fa8bbc7fca3aad40060f1ed7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>