Use legacy image upload for train

Commit 9c6667d
switched to use operators for uploading images on all
releases from train onwards.

Train jobs are no failing deploy, unable to find
the overcloud-full image.

This patch adds train to the relesase that use
the legacy upload script.

Depends-On: https://review.opendev.org/c/openstack/python-tripleoclient/+/801019

Change-Id: Iabcc33deaa494449799cf5ffe9dca44dcabed52e
Closes-Bug: #1936287

roles/overcloud-prep-images/tasks/overcloud-prep-images.yml

@@ -12,7 +12,7 @@
   block:
     - name: Run overcloud image upload - legacy
       when:
-        - release in ['queens', 'stein']
+        - release in ['queens', 'stein', 'train']
       shell: >
         set -o pipefail &&
         {{ working_dir }}/overcloud-image-upload.sh 2>&1 {{ timestamper_cmd }} >
@@ -21,7 +21,7 @@
 
     - name: Run overcloud image upload via tripleo-operator-ansible
       when:
-        - release not in ['queens', 'stein']
+        - release not in ['queens', 'stein', 'train']
       collections:
         - tripleo.operator
       include_role: