**Apache Airflow version**:
2.0.1

**Kubernetes version**:
Server Version: version.Info{Major:"1", Minor:"18+", GitVersion:"v1.18.9-eks-d1db3c", GitCommit:"d1db3c46e55f95d6a7d3e5578689371318f95ff9", GitTreeState:"clean", BuildDate:"2020-10-20T22:18:07Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}

**What happened**:
Clearing a failed subdag task with Downstream+Recursive does not automatically set the state of the parent dag to 'running' so that the downstream parent tasks can execute.

The work around is to manually set the state of the parent dag to running after clearing the subdag task

**What you expected to happen**:
With airflow version 1.10.4 the parent dag was automatically set to 'running' for this same scenario

**How to reproduce it**:
- Clear a failed subdag task selecting option for Downstream+Recursive
- See that all down stream tasks in the subdag as well as the parent dag have been cleared
- See that the parent dag is left in 'failed' state. 

tests/models/test_dag.py
with create_session() as session:
            session.add(DagModel(dag_id='dag_default_view_old', default_view=None))
            session.commit()
            orm_dag = session.query(DagModel).filter(DagModel.dag_id == 'dag_default_view_old').one()
        assert orm_dag.default_view is None
        assert orm_dag.get_default_view() == conf.get('webserver', 'dag_default_view').lower()
    def test_dag_is_deactivated_upon_dagfile_deletion(self):
        dag_id = 'old_existing_dag'
        dag_fileloc = "/usr/local/airflow/dags/non_existing_path.py"
        dag = DAG(
            dag_id,
            is_paused_upon_creation=True,
        )
        dag.fileloc = dag_fileloc
        session = settings.Session()
        with mock.patch.object(settings, "STORE_DAG_CODE", False):
            dag.sync_to_db(session=session)
        orm_dag = session.query(DagModel).filter(DagModel.dag_id == dag_id).one()
        assert orm_dag.is_active
        assert orm_dag.fileloc == dag_fileloc
        DagModel.deactivate_deleted_dags(list_py_file_paths(settings.DAGS_FOLDER))
        orm_dag = session.query(DagModel).filter(DagModel.dag_id == dag_id).one()
        assert not orm_dag.is_active
        
        session.execute(DagModel.__table__.delete().where(DagModel.dag_id == dag_id))
        session.close()
    def test_dag_naive_default_args_start_date_with_timezone(self):