Automatic merge from submit-queue (batch tested with PRs 59353, 59905, 53833). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Rename ConfigOK to KubeletConfigOk

This is a more accurate name for the condition, as it describes the
status of the Kubelet's configuration.

Also cleans up capitalization of internal names.

```release-note
The ConfigOK node condition has been renamed to KubeletConfigOk.
```