Run container-prep role before installing standalone

In order to set correct container tag from dlrn md5 sum
in container-image-prepare file, we need to run
container-prep role before deploying standalone.

Otherwise tripleo-ci-testing tag[1] will be used in periodic
line and this tag does not exists on quay.rdoproject.org.
It will fail the standalone deployment with image not found.

This patch fixes the same and now tag is properly set in
container-image-prepare[2]. The same tag will be set
in deploy_compute.sh script.

[1]. https://logserver.rdoproject.org/18/46118/3/check/periodic-tripleo-ci-centos-9-standalone-external-compute-target-host-master/1355bd7/logs/undercloud/home/zuul/containers-prepare-parameters.yaml.txt.gz

[2]. https://logserver.rdoproject.org/18/46118/4/check/periodic-tripleo-ci-centos-9-standalone-external-compute-target-host-master/a572928/logs/undercloud/home/zuul/containers-prepare-parameters.yaml.txt.gz

Signed-off-by: Chandan Kumar <chkumar@redhat.com>
Change-Id: I6cdb21b46385017b2c56771e2cf45f340013de02

roles/external-data-plane-management/tasks/deploy_standalone.yml

@@ -1,4 +1,8 @@
 ---
+- name: Set proper container params before deploying standalone
+  include_role:
+    name: container-prep
+
 - name: Deploy Standalone
   include_role:
     name: standalone

roles/external-data-plane-management/tasks/prepare_node.yml

@@ -9,3 +9,7 @@
 - name: Prepare the node for installation
   include_role:
     name: undercloud-setup
+
+- name: Set proper container params
+  include_role:
+    name: container-prep