Merge pull request #59793 from nikhita/staging-repos-boilerplate

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>.

staging: add boilerplate header

Follow up of https://github.com/kubernetes/kubernetes/pull/57656.

Adds boilerplate in the relevant staging repos so that they don't need to depend on code-generator's boilerplate.

**Release note**:

```release-note
NONE
```

/cc sttts fisherxu

Kubernetes-commit: 1a1643bb5df07d94330e1b16d182cee660533f91

vendor/k8s.io/apimachinery/pkg/runtime/scheme.go

@@ -431,6 +431,7 @@ func (s *Scheme) Convert(in, out interface{}, context interface{}) error {
 				return err
 			}
 			unstructuredOut.SetUnstructuredContent(content)
+			unstructuredOut.GetObjectKind().SetGroupVersionKind(gvk)
 			return nil
 		}