Adds tempest run command with --test-list option

In scenarios of setUpClass & tearDownClass failure
the xml output generated by tempest/subunit is inaccurate.
Generating a test-list will provide an accurate list of
tests that tempest attempted to execute based on all flags
passed to the 'tempest run' command.

Related-Bug: #1812254

Change-Id: I3eccee1c7b2c04c5766e713b1179bc645d3ccb82

tasks/tempest_run.yml

@@ -88,6 +88,23 @@
       # don't trigger ANSIBLE0013
       - skip_ansible_lint
 
+  - name: Generate test-list file
+    shell: |
+      set -e
+      if [ -d {{ tempest_venv_bin }} ];
+      then
+      . {{ tempest_venv_bin }}/activate
+      fi
+      tempest run --whitelist-file {{ tempest_test_whitelist_file_path }}{% if tempest_test_blacklist | length > 0 %} --blacklist-file {{ tempest_test_blacklist_file_path }}{% endif %} --list-tests &> {{ tempest_log_dir }}/test_list.txt
+    args:
+      chdir: "{{ tempest_workspace }}"
+      executable: /bin/bash
+    changed_when: false
+    failed_when: false
+    tags:
+      # don't trigger ANSIBLE0013
+      - skip_ansible_lint
+
 - name: Fail if tempest tests did not succeed
   assert:
     that: