Allow tempest cleanup delete resources based on prefix

A warning in command description of run cleanup first with dry-run
is added. The cleanup behavior is extended to allow users to delete
only resources if their name starts with a certain prefix.

Closes-Bug: #1945082
Change-Id: I65dfe051c891b3679538acec713e8616746c47f6
diff --git a/playbooks/devstack-tempest.yaml b/playbooks/devstack-tempest.yaml
index 269999c..f9b1db0 100644
--- a/playbooks/devstack-tempest.yaml
+++ b/playbooks/devstack-tempest.yaml
@@ -27,7 +27,8 @@
         init_saved_state: true
       when: (run_tempest_dry_cleanup is defined and run_tempest_dry_cleanup | bool) or
             (run_tempest_cleanup is defined and run_tempest_cleanup | bool) or
-            (run_tempest_fail_if_leaked_resources is defined and run_tempest_fail_if_leaked_resources | bool)
+            (run_tempest_fail_if_leaked_resources is defined and run_tempest_fail_if_leaked_resources | bool) or
+            (run_tempest_cleanup_prefix is defined and run_tempest_cleanup_prefix | bool)
 
     - name: Run Tempest version <= 26.0.0
       include_role: