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
"""Base metaclass of BaseOperator."""
    def __call__(cls, *args, **kwargs):
        """
        Called when you call BaseOperator(). In this way we are able to perform an action
        after initializing an operator no matter where  the ``super().__init__`` is called
        (before or after assign of new attributes in a custom operator).
        """
        obj: BaseOperator = type.__call__(cls, *args, **kwargs)
        
        obj.set_xcomargs_dependencies()
        
        obj._BaseOperator__instantiated = True
        return obj
@functools.total_ordering
class BaseOperator(Operator, LoggingMixin, TaskMixin, metaclass=BaseOperatorMeta):
    """