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.
airflow/models/baseoperator.py
ui_color = '#fff'  
    ui_fgcolor = '#000'  
    pool = ""  
    
    _base_operator_shallow_copy_attrs: Tuple[str, ...] = (
        'user_defined_macros',
        'user_defined_filters',
        'params',
        '_log',
    )
    
    shallow_copy_attrs: Tuple[str, ...] = ()
    
    operator_extra_links: Iterable['BaseOperatorLink'] = ()
    
    __serialized_fields: Optional[FrozenSet[str]] = None
    _comps = {
        'task_id',
        'dag_id',
        'owner',
        'email',
        'email_on_retry',
        'retry_delay',
        'retry_exponential_backoff',
        'max_retry_delay',
        'start_date',
        'depends_on_past',
        'wait_for_downstream',
        'priority_weight',