Set 'step_overcloud_prep_flavors' to false

As nova has been disabled by default, disable the flavor creation.

Change-Id: I7f6300407fcece11d98e7a251a5c026e7b1b2b79
Closes-Bug: #1894941

playbooks/quickstart-extras-overcloud-prep.yml

@@ -44,7 +44,8 @@
   tags:
     - overcloud-prep-flavors
   roles:
-    - overcloud-prep-flavors
+    - {role: overcloud-prep-flavors,
+       when: step_overcloud_prep_flavors|bool and undercloud_enable_nova|bool}
 
 # Prepare the undercloud networks for the overcloud deployment
 - name: Prepare the undercloud networks for the overcloud deployment

roles/extras-common/defaults/main.yml

@@ -110,6 +110,13 @@ undercloud_enable_nova: >-
   false
   {%- endif %}
 
+step_overcloud_prep_flavors: >-
+  {% if release in ['newton','ocata','pike','queens','rocky','stein','train', 'ussuri'] -%}
+  true
+  {%- else -%}
+  false
+  {%- endif -%}
+
 # Set the location for the downloaded amphora image when download_amphora is true
 octavia_amphora_path: >-
   {% if release in ['queens', 'rocky'] -%}