Fix returning module parameters for iam_role (ansible#30669)

* remove iam_role= from module.exit_json() to match return docs.

* Add back old iam_role= for backwards compat

lib/ansible/modules/cloud/amazon/iam_role.py

@@ -295,7 +295,7 @@ def create_or_update_role(connection, module):
     role = get_role(connection, module, params['RoleName'])
 
     role['attached_policies'] = get_attached_policy_list(connection, module, params['RoleName'])
-    module.exit_json(changed=changed, iam_role=camel_dict_to_snake_dict(role))
+    module.exit_json(changed=changed, iam_role=camel_dict_to_snake_dict(role), **camel_dict_to_snake_dict(role))
 
 
 def destroy_role(connection, module):