Airflow v2.0b3
 Kubernetes v1.19.3

Discovered issue while testing KubernetesPodOperator (haven't tested with other operator).
If I create a multiline string using """ """", add some variables inside (Jinja templating), then use this string as an argument to KubernetesPodOperator:
- In Graph View DAG is not visible (just gray area where it should be a digraph);
- in browser's web console i see the following error:

`Uncaught TypeError: node is undefined
    preProcessGraph http://localhost:8080/static/dist/dagre-d3.min.js:103
    preProcessGraph http://localhost:8080/static/dist/dagre-d3.min.js:103
    fn http://localhost:8080/static/dist/dagre-d3.min.js:103
    call http://localhost:8080/static/dist/d3.min.js:3
    draw http://localhost:8080/graph?dag_id=mydag&execution_date=mydate
    expand_group http://localhost:8080/graph?dag_id=mydag&execution_date=mydate
    <anonymous> http://localhost:8080/graph?dag_id=mydag&execution_date=mydate`

Tree view works without issues in this case. The DAG succeeds.
tests/utils/test_task_group.py
"""
    Tests that prefix_group_id turns on/off prefixing of task_id with group_id.
    """
    execution_date = pendulum.parse("20200101")
    with DAG("test_build_task_group_with_prefix", start_date=execution_date) as dag:
        task1 = DummyOperator(task_id="task1")
        with TaskGroup("group234", prefix_group_id=False) as group234:
            task2 = DummyOperator(task_id="task2")
            with TaskGroup("group34") as group34:
                task3 = DummyOperator(task_id="task3")
                with TaskGroup("group4", prefix_group_id=False) as group4:
                    task4 = DummyOperator(task_id="task4")
        task5 = DummyOperator(task_id="task5")
        task1 >> group234
        group34 >> task5
    assert task2.task_id == "task2"
    assert group34.group_id == "group34"
    assert task3.task_id == "group34.task3"
    assert group4.group_id == "group34.group4"
    assert task4.task_id == "task4"
    assert task5.task_id == "task5"
    assert group234.get_child_by_label("task2") == task2
    assert group234.get_child_by_label("group34") == group34
    assert group4.get_child_by_label("task4") == task4