**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
"""
        Test that Graph, Tree & Dag Details View uses the DagBag already created in views.py
        instead of creating a new one.
        """
        url = f'{endpoint}?dag_id=example_bash_operator'
        resp = self.client.get(url, follow_redirects=True)
        self.check_content_in_response('example_bash_operator', resp)
    @parameterized.expand(
        [
            ("hello\nworld", r'\"conf\":{\"abc\":\"hello\\nworld\"}'),
            ("hello'world", r'\"conf\":{\"abc\":\"hello\\u0027world\"}'),
            ("<script>", r'\"conf\":{\"abc\":\"\\u003cscript\\u003e\"}'),
            ("\"", r'\"conf\":{\"abc\":\"\\\"\"}'),
        ]
    )
    def test_escape_in_tree_view(self, test_str, expected_text):
        dag = self.dagbag.get_dag('test_tree_view')
        dag.create_dagrun(
            execution_date=self.EXAMPLE_DAG_DEFAULT_DATE,
            start_date=timezone.utcnow(),
            run_type=DagRunType.MANUAL,
            state=State.RUNNING,
            conf={"abc": test_str},
        )
        url = 'tree?dag_id=test_tree_view'
        resp = self.client.get(url, follow_redirects=True)
        self.check_content_in_response(expected_text, resp)
    def test_dag_details_trigger_origin_tree_view(self):