switched to use built in function for validation

lib/ansible/modules/system/service.py

@@ -1463,9 +1463,8 @@ def main():
             arguments = dict(aliases=['args'], default=''),
         ),
         supports_check_mode=True
+        required_one_of=[['state', 'enabled']],
     )
-    if module.params['state'] is None and module.params['enabled'] is None:
-        module.fail_json(msg="Neither 'state' nor 'enabled' set")
 
     service = Service(module)