Description of problem:
Creating volumesnapshot does not generate volumesnapshotdata.

Version-Release number of selected component (if applicable):
openshift v3.7.0-0.153.0
kubernetes v1.7.6+a08f5eeb62
etcd 3.2.8

How reproducible:
Always

Steps to Reproduce:
1. Set up OCP cluster.
2. Start snapshot controller and provisioner.
# snapshot-controller -cloudprovider=gce -kubeconfig=$HOME/.kube/config &> controller.log &
# snapshot-pv-provisioner -cloudprovider=gce -kubeconfig=$HOME/.kube/config &> provisioner.log &
3. Login in as end user, and create project, pvc and pod.
$ cat pvc.yaml 
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: gce-pvc
spec:
  accessModes: [ "ReadWriteOnce" ]
  resources:
    requests:
      storage: 3Gi
4. Check pvc is bound with dynamic provisioned pv/volume, check pod is runing.
5. Write some data into the mounted volume path.
6. Create a snapshot via cluster-admin (Due to bug 1502945, can not use end user here).
$ cat snapshot.yaml 
apiVersion: volume-snapshot-data.external-storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: snapshot-1
  namespace: myns
spec:
  persistentVolumeClaimName: gce-pvc
7. Check volumesnapshot and volumesnapshotdata.
# oc get volumesnapshot,volumesnapshotdata --all-namespaces

Actual results:
volumesnapshot exist, but NO volumesnapshotdata.

Expected results:
There are volumesnapshotdata which co-exist with volumesnapshot.

Additonal info:
snapshot.log.gzip which contains controller and provisioner logs.