Automatic merge from submit-queue. 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>.
[Prometheus addon] Use StatefulSet
This PR changes prometheus server manifest from deployment to statefulset.
Version label is removed from pods because statefulset disallows updating selectors.
```release-note
NONE
```
/cc @branch @kawych