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>.
Change RBAC storage version to v1 for 1.9
v1 was introduced in 1.8, but storage version remained at v1beta1 to accommodate HA rolling upgrades. in 1.9, we can change the persisted and preferred version to v1
```release-note
RBAC objects are now stored in etcd in v1 format. After completing an upgrade to 1.9, RBAC objects (Roles, RoleBindings, ClusterRoles, ClusterRoleBindings) should be migrated to ensure all persisted objects are written in `v1` format, prior to `v1alpha1` support being removed in a future release.
```
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