Fix for runtest.tempest_generated_config

added default values for auth section:
- admin_domain_name = Default
- use_dynamic_credentials = True

Change-Id: I51589539f4088391ce25314713e57fc164b89d7e
Related-Prod: https://mirantis.jira.com/browse/PROD-18039
diff --git a/_modules/runtest/tempest_sections/auth.py b/_modules/runtest/tempest_sections/auth.py
index 83a5748..a052100 100644
--- a/_modules/runtest/tempest_sections/auth.py
+++ b/_modules/runtest/tempest_sections/auth.py
@@ -20,7 +20,7 @@
 
     @property
     def admin_domain_name(self):
-        pass
+        return 'Default'
 
     @property
     def admin_password(self):
@@ -58,5 +58,5 @@
 
     @property
     def use_dynamic_credentials(self):
-        pass
+        return True