Automatic merge from submit-queue
Fix system container detection in kubelet on systemd
```release-note
Fix system container detection in kubelet on systemd.
This fixed environments where CPU and Memory Accounting were not enabled on the unit
that launched the kubelet or docker from reporting the root cgroup when
monitoring usage stats for those components.
```
Fixes https://github.com/kubernetes/kubernetes/issues/25909
/cc @kubernetes/sig-node @kubernetes/rh-cluster-infra @vishh @dchen1107