gerrit: don't chown mariadb container directory

We are currently re-chowning the running db directories back to root,
causing havoc for the db.  Drop the explicit permissions to avoid
this.

Change-Id: I8d8ce5c62c660875d5c6eed54c686996576ec9df

playbooks/roles/gerrit/tasks/main.yaml

@@ -285,16 +285,14 @@
   when: gerrit_redirect_vhost is defined
   notify: gerrit Reload apache2
 
-- name: Start gerrit
-  include_tasks: start.yaml
-
+# NOTE(ianw) This deliberately does not set owner/group/mode, as the
+# mariadb container chowns this directory to be owned by a
+# container-internal user and drops root privileges.  We don't want to
+# reset this from outside the container.
 - name: Setup reviewdb directory for mariadb
   file:
     state: directory
     path: /home/gerrit2/reviewdb
-    owner: root
-    group: root
-    mode: 0755
 
 - name: Set up root mariadb conf file
   template:
@@ -302,6 +300,9 @@
     dest: /root/.gerrit_db.cnf
     mode: 0400
 
+- name: Start gerrit
+  include_tasks: start.yaml
+
 - name: Set up cron job to optmize git repos
   cron:
     name: optmize-git-repos