Add roles to create_user test (#20773)
Add roles to create_user test (#20773)

Flask App Builder 3.4.3 made role and conf_password obligatory
when creating user:
https://github.com/dpgaspar/Flask-AppBuilder/pull/1758

Our test for user creation did not have the role set (though the
UI used it and the cient also allows to set it).

This change adds the `roles` in our tests to enable upgrade
to FAB 3.4.3 for the CI (currently tests in main fail because of
the test failure)
nathanielvarona/airflow,nathanielvarona/airflow,cfei18/incubator-airflow,lyft/incubator-airflow,nathanielvarona/airflow,bolkedebruin/airflow,nathanielvarona/airflow,bolkedebruin/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,mistercrunch/airflow,apache/airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,apache/airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,lyft/incubator-airflow,bolkedebruin/airflow,apache/airflow,Acehaidrey/incubator-airflow,apache/airflow,lyft/incubator-airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,mistercrunch/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,apache/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,mistercrunch/airflow,cfei18/incubator-airflow,mistercrunch/airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,apache/airflow