On newer COS M97 images, cgroupv2 is enabled out of the box. It is
enabled using default systemd configuration and does not have
`systemd.unified_cgroup_hierarchy` present `/proc/cmdline`. As a result, the
check for manual cgroupv2 enablement should be improved to not only check
`/proc/cmdline`, but also to see if it's enabled on the system using `stat
-fc %T /sys/fs/cgroup/`
Signed-off-by: David Porter <porterdavid@google.com>
