Add cinder cron container to run db purge

The cinder db purge cron job is created by puppet in
/var/spool/cron/cinder. This creates a cron container to run
that in an environment where it has access to cinder.conf
and the cinder-manage binaries.

Change-Id: I02ae32a6dcd8569e2e2390063d4d935d05545a78
Partial-bug: #1701254

docker/services/cinder-api.yaml

@@ -86,6 +86,17 @@ outputs:
             - path: /var/log/cinder
               owner: cinder:cinder
               recurse: true
+        /var/lib/kolla/config_files/cinder_api_cron.json:
+          command: /usr/sbin/crond -n
+          config_files:
+            - source: "/var/lib/kolla/config_files/src/*"
+              dest: "/"
+              merge: true
+              preserve_properties: true
+          permissions:
+            - path: /var/log/cinder
+              owner: cinder:cinder
+              recurse: true
       docker_config:
         step_2:
           cinder_api_init_logs:
@@ -140,6 +151,21 @@ outputs:
                       - ''
             environment:
               - KOLLA_CONFIG_STRATEGY=COPY_ALWAYS
+          cinder_api_cron:
+            image: *cinder_api_image
+            net: host
+            privileged: false
+            restart: always
+            volumes:
+              list_concat:
+                - {get_attr: [ContainersCommon, volumes]}
+                -
+                  - /var/lib/kolla/config_files/cinder_api_cron.json:/var/lib/kolla/config_files/config.json:ro
+                  - /var/lib/config-data/puppet-generated/cinder/:/var/lib/kolla/config_files/src:ro
+                  - /var/log/containers/cinder:/var/log/cinder
+            environment:
+              - KOLLA_CONFIG_STRATEGY=COPY_ALWAYS
+
       host_prep_tasks:
         - name: create persistent logs directory
           file: