Previous versions (before 2.0) allowed for granular can_edit DAG permissions so that different user groups can trigger different DAGs and access control is more specific. Since 2.0 it seems that this does not work as expected.

How to reproduce:
Create a copy of the VIEWER role, try adding it can dag edit on a specific DAG. **Expected Result:** user can trigger said DAG. **Actual Result:** user access is denied.

It seems to be a new parameter was added: **can create on DAG runs** and without it the user cannot run DAGs, however, with it, the user can run all DAGs without limitations and I believe this is an unintended use.

airflow/www/views.py
selected_dag_ids = {unquote(dag_id) for dag_id in request.form.getlist('dag_ids') if dag_id}
        if selected_dag_ids:
            filter_dag_ids = selected_dag_ids.intersection(allowed_dag_ids)
        else:
            filter_dag_ids = allowed_dag_ids
        if not filter_dag_ids:
            return wwwutils.json_response({})
        payload = {}
        dag_state_stats = dag_state_stats.filter(dr.dag_id.in_(filter_dag_ids))  
        data = {}
        for dag_id, state, count in dag_state_stats:
            if dag_id not in data:
                data[dag_id] = {}
            data[dag_id][state] = count
        for dag_id in filter_dag_ids:
            payload[dag_id] = []
            for state in State.dag_states:
                count = data.get(dag_id, {}).get(state, 0)
                payload[dag_id].append({'state': state, 'count': count})
        return wwwutils.json_response(payload)
    @expose('/task_stats', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @provide_session
    def task_stats(self, session=None):