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
super().__setattr__(key, value)
        if self._lock_for_execution:
            
            return
        if self.__instantiated and key in self.template_fields:
            
            
            
            
            self.set_xcomargs_dependencies()
    def add_inlets(self, inlets: Iterable[Any]):
        """Sets inlets to this operator"""
        self._inlets.extend(inlets)
    def add_outlets(self, outlets: Iterable[Any]):
        """Defines the outlets of this operator"""
        self._outlets.extend(outlets)
    def get_inlet_defs(self):
        """:return: list of inlets defined for this operator"""
        return self._inlets
    def get_outlet_defs(self):