Automatic merge from submit-queue
Generate valid container id in fake docker client.
Fixes https://github.com/kubernetes/kubernetes/issues/41488.
This PR generates valid container id by hashing container name. So that dockershim checkpoint won't report `checkpoint key XXX is not valid` error.
This PR also reverts #41460.
@yujuhong @freehan /cc @kubernetes/sig-node-pr-reviews