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/zuul.d/tempest-specific.yaml b/zuul.d/tempest-specific.yaml
index 10490b4..296682e 100644
--- a/zuul.d/tempest-specific.yaml
+++ b/zuul.d/tempest-specific.yaml
@@ -58,6 +58,8 @@
       Base integration test with Neutron networking, IPv6 and py3.
     vars:
       tox_envlist: full
+      run_tempest_cleanup: true
+      run_tempest_cleanup_prefix: true
       devstack_localrc:
         USE_PYTHON3: true
         FORCE_CONFIG_DRIVE: true