Add zuul-operator-upload-image job

It seems like the zuul-operator-promote-image job does not
upload the image. This change adds a new gate job to upload
the image and fix the promote job.

Depends-On: https://review.opendev.org/727868
Change-Id: Ic3b41e3b29182135f71dc1adf8c6ebd9c26d798d

.zuul.yaml

@@ -56,6 +56,23 @@
           0s5nzOti9LdQNCkKVAvRCsOyp7+U9zvf6LHQhO35ivW3vrSmEfyqQqUVdJMBHhBE8M0jj
           AYLhYdFc748RTCVJzka6uAQ69QJuv0wSP0+MHKy39OrnOSDZUGm1dkeTQwqpWA=
 
+- job:
+    description: Build Docker images and upload to Docker Hub.
+    name: zuul-operator-upload-image
+    parent: opendev-upload-docker-image
+    allowed-projects: zuul/zuul-operator
+    secrets:
+      name: docker_credentials
+      secret: zuul-operator-dockerhub
+      pass-to-parent: true
+    requires:
+      - zuul-container-image
+      - zuul-registry-container-image
+      - nodepool-container-image
+    provides:
+      - zuul-operator-container-image
+    vars: *image_vars
+
 - job:
     description: Promote previously uploaded images.
     name: zuul-operator-promote-image
@@ -77,9 +94,9 @@
             dependencies: zuul-operator-build-image
     gate:
       jobs:
-        - zuul-operator-build-image
+        - zuul-operator-upload-image
         - zuul-operator-functional-k8s:
-            dependencies: zuul-operator-build-image
+            dependencies: zuul-operator-upload-image
     promote:
       jobs:
         - zuul-operator-promote-image