**Description**
In the trigger page, there is a text area to enter (optional) conf json. It would be great if a sample JSON can be provided programatically while defining DAG

**Use case / motivation**

This will improve usability of the UI that triggers a DAG

tests/www/test_views.py
'state_color_mapping',
            'airflow_version',
            'git_version',
            'k8s_or_k8scelery_executor',
            
            'url_for_asset',
            
            'scheduler_job',
            
            'macros',
        ]
        for key in keys_to_delete:
            del result[key]
        return result
class TestBase(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        settings.configure_orm()
        cls.session = settings.Session
        cls.app = application.create_app(testing=True)
        cls.appbuilder = cls.app.appbuilder  
        cls.app.config['WTF_CSRF_ENABLED'] = False
        cls.app.jinja_env.undefined = jinja2.StrictUndefined
    @classmethod
    def tearDownClass(cls) -> None:
        clear_db_runs()
    def setUp(self):
        self.client = self.app.test_client()
        self.login()
    def login(self, username='test', password='test'):