Update 1.2.4-rc1 for prow staging rc master

Author: saikat-royc

deploy/kubernetes/images/prow-gke-release-staging-rc-master/image.yaml

@@ -53,5 +53,5 @@ metadata:
 imageTag:
   name: k8s.gcr.io/cloud-provider-gcp/gcp-compute-persistent-disk-csi-driver
   newName: gcr.io/k8s-staging-cloud-provider-gcp/gcp-compute-persistent-disk-csi-driver
-  newTag: "v1.3.4-rc1"
+  newTag: "v1.2.4-rc1"
 ---