Improve messaging on resize

- we now provide clear message to user what to do when cloudprovider resizing is finished
  and file system resizing is needed.
- add a event when resizing is successful.
- Use Patch for updating PVCs in both kubelet and controller-manager
- Extract updating pvc util function in one place.
- Only update resize conditions on progress

pkg/controller/volume/expand/sync_volume_resize.go

@@ -25,8 +25,8 @@ import (
 	"k8s.io/apimachinery/pkg/util/wait"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/kubernetes/pkg/controller/volume/expand/cache"
-	"k8s.io/kubernetes/pkg/controller/volume/expand/util"
 	"k8s.io/kubernetes/pkg/util/goroutinemap/exponentialbackoff"
+	"k8s.io/kubernetes/pkg/volume/util"
 	"k8s.io/kubernetes/pkg/volume/util/operationexecutor"
 )
 
@@ -96,6 +96,8 @@ func markPVCResizeInProgress(pvcWithResizeRequest *cache.PVCWithResizeRequest, k
 		LastTransitionTime: metav1.Now(),
 	}
 	conditions := []v1.PersistentVolumeClaimCondition{progressCondition}
+	newPVC := pvcWithResizeRequest.PVC.DeepCopy()
+	newPVC = util.MergeResizeConditionOnPVC(newPVC, conditions)
 
-	return util.UpdatePVCCondition(pvcWithResizeRequest.PVC, conditions, kubeClient)
+	return util.PatchPVCStatus(pvcWithResizeRequest.PVC /*oldPVC*/, newPVC, kubeClient)
 }