Merge pull request kubernetes#4147 from kinvolk/rata/userns

KEP-127: Update feature gate name and update last-milestone for 1.29

Author: k8s-ci-robot

keps/sig-node/127-user-namespaces/kep.yaml

@@ -16,12 +16,12 @@ approvers:
   - "@derekwaynecarr"
 
 stage: alpha
-latest-milestone: "v1.28"
+latest-milestone: "v1.29"
 milestone:
   alpha: "v1.25"
 
 feature-gates:
-  - name: UserNamespacesStatelessPodsSupport
+  - name: UserNamespacesSupport
     components:
       - kubelet
       - kube-apiserver