**Apache Airflow version**: 2.0.0

**Kubernetes version (if you are using kubernetes)** (use `kubectl version`): n/a

**Environment**: Linux

- **Cloud provider or hardware configuration**: amd64
- **OS** (e.g. from /etc/os-release): Centos 7
- **Kernel** (e.g. `uname -a`):
- **Install tools**: pip
- **Others**:

**What happened**:

The field `sql` is rendered as a serialized json `["select 1 from dual", "select 2 from dual"]` instead of a list of syntax-highlighted SQL statements.

![image](https://user-images.githubusercontent.com/5377410/106365382-2f8a1e80-6370-11eb-981a-43bf71e7b396.png)

**What you expected to happen**:

`lists` and `dicts` should be rendered as lists and dicts rather than serialized json unless the `template_field_renderer` is `json`

![image](https://user-images.githubusercontent.com/5377410/106365216-f3a28980-636e-11eb-9c48-15deb1fbe0d7.png)


**How to reproduce it**:

```
from airflow import DAG
from airflow.providers.oracle.operators.oracle import OracleOperator

with DAG("demo", default_args={owner='airflow'}, start_date= pendulum.yesterday(), schedule_interval='@daily',) as dag:
    OracleOperator(task_id='single', sql='select 1 from dual')
    OracleOperator(task_id='list', sql=['select 1 from dual', 'select 2 from dual'])
```

**Anything else we need to know**:

Introduced by #11061, .

A quick and dirty work-around:

Edit file [airflow/www/views.py](https://github.com/PolideaInternal/airflow/blob/13ba1ec5494848d4a54b3291bd8db5841bfad72e/airflow/www/views.py#L673)

```
            if renderer in renderers:
-                if isinstance(content, (dict, list)):
+               if isinstance(content, (dict, list)) and renderer is renderers['json']:
                    content = json.dumps(content, sort_keys=True, indent=4)
                html_dict[template_field] = renderers[renderer](content)
```
airflow/www/views.py
[
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def rendered_templates(self):
        """Get rendered Dag."""
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        execution_date = request.args.get('execution_date')
        dttm = timezone.parse(execution_date)
        form = DateTimeForm(data={'execution_date': dttm})
        root = request.args.get('root', '')
        logging.info("Retrieving rendered templates.")
        dag = current_app.dag_bag.get_dag(dag_id)
        task = copy.copy(dag.get_task(task_id))
        ti = models.TaskInstance(task=task, execution_date=dttm)
        try:
            ti.get_rendered_template_fields()
        except AirflowException as e:  
            msg = "Error rendering template: " + escape(e)
            if e.__cause__:  
                msg += Markup("<br><br>OriginalError: ") + escape(e.__cause__)
            flash(msg, "error")
        except Exception as e:  
            flash("Error rendering template: " + str(e), "error")
        title = "Rendered Template"
        html_dict = {}
        renderers = wwwutils.get_attr_renderer()