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>.

Add statefulset conditions

**What this PR does / why we need it**: This PR adds conditions to statefulset status making it consistent with other controllers for v1. See linked issue for discussion.

/xref: https://github.com/kubernetes/kubernetes/issues/7856

**Special notes for your reviewer**:

**Release note**:

```release-note
StatefulSet status now has support for conditions, making it consistent with other core controllers in v1 
```