Automatic merge from submit-queue

Kubelet: Fix the description of MaxContainers kubelet flag.

Found this during code review.

The default number has been changed to `-1` and `1`. https://github.com/kubernetes/kubernetes/blob/82c488bd6ed00b7417ee32bf468d70f4dd18c25a/pkg/apis/componentconfig/v1alpha1/defaults.go#L279-L285
@yujuhong 

/cc @saad-ali This PR fixed incorrect doc.