Add snapshot controller metrics

Signed-off-by: Grant Griffiths <grant@portworx.com>

pkg/utils/util.go

@@ -519,3 +519,8 @@ func IsSnapshotReady(snapshot *crdv1.VolumeSnapshot) bool {
 	}
 	return true
 }
+
+// IsSnapshotCreated indicates that the snapshot has been cut on a storage system
+func IsSnapshotCreated(snapshot *crdv1.VolumeSnapshot) bool {
+	return snapshot.Status != nil && snapshot.Status.CreationTime != nil
+}