Remove gke suffix from rc tag of image

Author: davidz627

deploy/kubernetes/overlays/prow-gke-staging/controller_images.yaml

@@ -11,4 +11,4 @@ spec:
         - name: csi-attacher
           image: gcr.io/gke-release-staging/csi-attacher:v1.0.1-gke.0
         - name: gce-pd-driver
-          image: gcr.io/gke-release-staging/gcp-compute-persistent-disk-csi-driver:v0.4.0-rc1-gke.0
+          image: gcr.io/gke-release-staging/gcp-compute-persistent-disk-csi-driver:v0.4.0-rc1

deploy/kubernetes/overlays/prow-gke-staging/node_images.yaml

@@ -9,4 +9,4 @@ spec:
         - name: csi-driver-registrar
           image: gcr.io/gke-release-staging/csi-node-driver-registrar:v1.0.1-gke.0
         - name: gce-pd-driver
-          image: gcr.io/gke-release-staging/gcp-compute-persistent-disk-csi-driver:v0.4.0-rc1-gke.0
+          image: gcr.io/gke-release-staging/gcp-compute-persistent-disk-csi-driver:v0.4.0-rc1