Add Gerrit 3.7 -> 3.8 upgrade job

Now that we have a mostly working 3.8 image it is time to test the
upgrade from 3.7 (what we run in prod) to 3.8 (what we will eventually
run in prod).

Change-Id: Ied8bae6b80cff79668a293ae2f30498abbf6839d

playbooks/zuul/upgrade-review.yaml

@@ -86,8 +86,8 @@
   vars:
     gerrit_container_image: docker.io/opendevorg/gerrit:3.8
     gerrit_run_init: true
-    # Gerrit 3.6 -> 3.7 upgrade requires an offline reindex
-    gerrit_run_reindex: true
+    # Gerrit 3.7 -> 3.8 upgrade does not require an offline reindex
+    gerrit_run_reindex: false
 
 - hosts: "review:!disabled"
   name: "Post upgrade config check"

zuul.d/project.yaml

@@ -75,14 +75,13 @@
               - name: opendev-buildset-registry
               - name: system-config-build-image-gerrit-3.8
                 soft: true
-        # TODO update upgrade job to do 3.7 -> 3.8 upgrades
-        #- system-config-upgrade-review:
-        #    dependencies:
-        #      - name: opendev-buildset-registry
-        #      - name: system-config-build-image-gerrit-3.7
-        #        soft: true
-        #      - name: system-config-build-image-gerrit-3.8
-        #        soft: true
+        - system-config-upgrade-review:
+            dependencies:
+              - name: opendev-buildset-registry
+              - name: system-config-build-image-gerrit-3.7
+                soft: true
+              - name: system-config-build-image-gerrit-3.8
+                soft: true
         - system-config-build-image-refstack
         - system-config-run-refstack:
             dependencies:

zuul.d/system-config-run.yaml

@@ -1137,21 +1137,20 @@
     vars:
       zuul_test_gerrit_version: '3.8'
 
-# TODO Update the upgrade job to test 3.7 -> 3.8 upgrades
-#- job:
-#    name: system-config-upgrade-review
-#    parent: system-config-run-review-base
-#    description: |
-#      Test we can upgrade a gerrit 3.7 to 3.8
-#    requires:
-#      - gerrit-3.7-container-image
-#      - gerrit-3.8-container-image
-#    vars:
-#      run_playbooks:
-#        - playbooks/letsencrypt.yaml
-#        - playbooks/zuul/upgrade-review.yaml
-#      run_test_playbook: playbooks/zuul/test-review.yaml
-#      zuul_test_gerrit_version: '3.7'
+- job:
+    name: system-config-upgrade-review
+    parent: system-config-run-review-base
+    description: |
+      Test we can upgrade a gerrit 3.7 to 3.8
+    requires:
+      - gerrit-3.7-container-image
+      - gerrit-3.8-container-image
+    vars:
+      run_playbooks:
+        - playbooks/letsencrypt.yaml
+        - playbooks/zuul/upgrade-review.yaml
+      run_test_playbook: playbooks/zuul/test-review.yaml
+      zuul_test_gerrit_version: '3.7'
 
 - job:
     name: system-config-run-static