Fallback to stop-the-world compaction on kernel < 5.13 hosts

Some test bots are running 5.4 kernel on which SIGBUS is being observed.
There is a request pending to upgrade the host kernels. Until then
don't use userfaultfd on such old kernels.

Test: ART_USE_READ_BARRIER=false art/test/testrunner/testrunner.py --host
Bug: 242181443
Bug: 160737021
Change-Id: I1c1f6662d773927c5938cbb054974e295f83580e