### Apache Airflow version

2.3.3 (latest released)

### What happened

An URL I saved in the past, `https://astronomer.astronomer.run/dx4o2568/home?tags=test`,  has the tag field in the query parameter though I was not aware of this. When I clicked on the URL, I was confused because I did not see any DAGs when I should have a bunch.

After closer inspection, I realized that the URL has the tag field in the query parameter but then noticed that the tag box in the Airflow UI wasn't properly populated.

![screen_shot_2022-07-12_at_8 11 07_am](https://user-images.githubusercontent.com/5952735/182496710-601b4a98-aacb-4482-bb9f-bb3fdf9e265f.png)


### What you think should happen instead

When I clicked on the URL, the tag box should have been populated with the strings in the URL.

### How to reproduce

Start an Airflow deployment with some DAGs and add the tag query parameter. More specifically, it has to be a tag that is not used by any DAG.

### Operating System

N/A

### Versions of Apache Airflow Providers

_No response_

### Deployment

Astronomer

### Deployment details

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

"""Triggers DAG Run."""
        dag_id = request.values.get("dag_id")
        run_id = request.values.get("run_id")
        origin = get_safe_url(request.values.get("origin"))
        unpause = request.values.get("unpause")
        request_conf = request.values.get("conf")
        request_execution_date = request.values.get("execution_date", default=timezone.utcnow().isoformat())
        is_dag_run_conf_overrides_params = conf.getboolean("core", "dag_run_conf_overrides_params")
        dag = get_airflow_app().dag_bag.get_dag(dag_id)
        dag_orm = session.query(models.DagModel).filter(models.DagModel.dag_id == dag_id).first()
        if not dag_orm:
            flash(f"Cannot find dag {dag_id}")
            return redirect(origin)
        if dag_orm.has_import_errors:
            flash(f"Cannot create dagruns because the dag {dag_id} has import errors", "error")
            return redirect(origin)
        if request.method == "GET":
            
            default_conf = ""
            doc_md = wwwutils.wrapped_markdown(getattr(dag, "doc_md", None))
            form = DateTimeForm(data={"execution_date": request_execution_date})
            if request_conf:
                default_conf = request_conf
            else:
                try:
                    default_conf = json.dumps(
                        {str(k): v.resolve(suppress_exception=True) for k, v in dag.params.items()}, indent=4
                    )
                except TypeError:
                    flash("Could not pre-populate conf field due to non-JSON-serializable data-types")