Update cloud-build configuration

cloudbuild.yaml

@@ -5,16 +5,19 @@
 options:
   substitution_option: ALLOW_LOOSE
 steps:
-  - name: "gcr.io/k8s-testimages/gcb-docker-gcloud:v20190906-745fed4"
-    entrypoint: make
+  - name: 'gcr.io/k8s-testimages/gcb-docker-gcloud:v20200422-b25d964'
+    entrypoint: bash
     env:
       - DOCKER_CLI_EXPERIMENTAL=enabled
       - TAG=$_GIT_TAG
       - BASE_REF=$_PULL_BASE_REF
       - REGISTRY=gcr.io/k8s-staging-ingress-nginx
+      - HOME=/root
     args:
-      - release
-
+    - -c
+    - |
+      gcloud auth configure-docker \
+      && make release
 substitutions:
   # _GIT_TAG will be filled with a git-based tag for the image, of the form vYYYYMMDD-hash, and
   # can be used as a substitution