Fix flaky OOM tests

If cgroup swap memory limit isn't enabled, then
the -m flag doesn't work and the container that is created for
both of these tests is very large. Because we are trying to run the
containers out of memory, this takes a very long time and causes the
tests to fail most of the time.

Follow-up to #17913

Signed-off-by: Christopher Jones <tophj@linux.vnet.ibm.com>