docker: Run mistral-db-manage populate at step 5

This resolves issues in loading some of Mistral openstack
actions which appears to require endpoints to be running first
before fake clients can be initialized properly.

Change-Id: Ia588e5ec8880da1df95a33696b5b8c9e72ac49e2
Closes-bug: #1728682

docker/services/mistral-api.yaml

@@ -148,22 +148,6 @@ outputs:
                   - /var/lib/config-data/mistral/etc/mistral/:/etc/mistral/:ro
                   - /var/log/containers/mistral:/var/log/mistral
             command: "/usr/bin/bootstrap_host_exec mistral_api su mistral -s /bin/bash -c 'mistral-db-manage --config-file /etc/mistral/mistral.conf upgrade head'"
-          mistral_db_populate:
-            start_order: 1
-            image: *mistral_api_image
-            net: host
-            privileged: false
-            detach: false
-            user: root
-            volumes:
-              list_concat:
-                - {get_attr: [ContainersCommon, volumes]}
-                -
-                  - /var/lib/config-data/mistral/etc/mistral/:/etc/mistral/:ro
-                  - /var/log/containers/mistral:/var/log/mistral
-            # NOTE: dprince this requires that we install openstack-tripleo-common into
-            # the Mistral API image so that we get tripleo* actions
-            command: "/usr/bin/bootstrap_host_exec mistral_api su mistral -s /bin/bash -c 'mistral-db-manage --config-file /etc/mistral/mistral.conf populate'"
         step_4:
           mistral_api:
             start_order: 15
@@ -180,6 +164,23 @@ outputs:
                   - /var/log/containers/mistral:/var/log/mistral
             environment:
               - KOLLA_CONFIG_STRATEGY=COPY_ALWAYS
+        step_5:
+          mistral_db_populate:
+            start_order: 1
+            image: *mistral_api_image
+            net: host
+            privileged: false
+            detach: false
+            user: root
+            volumes:
+              list_concat:
+                - {get_attr: [ContainersCommon, volumes]}
+                -
+                  - /var/lib/config-data/mistral/etc/mistral/:/etc/mistral/:ro
+                  - /var/log/containers/mistral:/var/log/mistral
+            # NOTE: dprince this requires that we install openstack-tripleo-common into
+            # the Mistral API image so that we get tripleo* actions
+            command: "/usr/bin/bootstrap_host_exec mistral_api su mistral -s /bin/bash -c 'mistral-db-manage --config-file /etc/mistral/mistral.conf populate'"
       host_prep_tasks:
         - name: create persistent logs directory
           file: