Merge pull request #58393 from deads2k/agg-02-ga

Automatic merge from submit-queue (batch tested with PRs 54071, 58393). 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>.

promote aggregation API to v1

Finishing https://github.com/kubernetes/features/issues/263 as discussed in apimachinery

The API has been available since 1.6 and beta since 1.7.  Openshift has been using it for about a year and service catalog (@pmorie) and metrics server (@piosz @DirectXMan12) have both been using too.  The feature and the API have both been stable over that time.

@kubernetes/sig-api-machinery-api-reviews @kubernetes/api-approvers 

/assign lavalamp
/assign smarterclayton


```release-note
Promoting the apiregistration.k8s.io (aggregation) to GA
```

pkg/generated/openapi/BUILD

@@ -64,6 +64,7 @@ openapi_library(
         "k8s.io/apiserver/pkg/apis/example/v1",
         "k8s.io/apiserver/pkg/apis/example2/v1",
         "k8s.io/client-go/pkg/version",
+        "k8s.io/kube-aggregator/pkg/apis/apiregistration/v1",
         "k8s.io/kube-aggregator/pkg/apis/apiregistration/v1beta1",
         "k8s.io/metrics/pkg/apis/custom_metrics/v1beta1",
         "k8s.io/metrics/pkg/apis/metrics/v1alpha1",