Automatic merge from submit-queue
cgroup names created by kubelet should be lowercased
**What this PR does / why we need it**:
This PR modifies the kubelet to create cgroupfs names that are lowercased. This better aligns us with the naming convention for cgroups v2 and other cgroup managers in ecosystem (docker, systemd, etc.)
See: https://www.kernel.org/doc/Documentation/cgroup-v2.txt
"2-6-2. Avoid Name Collisions"
**Special notes for your reviewer**:
none
**Release note**:
```release-note
kubelet created cgroups follow lowercase naming conventions
```