**Update**

We discussed and decide this CLI should always only clean up pods created by Airflow.

<hr>

### Description

Currently command `kubernetes cleanup-pods` cleans up Pods that meet specific conditions in a given namespace.

Underlying code: https://github.com/apache/airflow/blob/2.0.1/airflow/cli/commands/kubernetes_command.py#L70

### Use case / motivation

The problem to me is: users may have other non-Airflow stuff running in this specific namespace, and they may want to have different strategy/logic for Pod cleaning-up for these non-Airflow pods.

We may want to have an additional boolean flag for this command, like `--only-airflow-pods`, so that users can decide if they only want to clean up Airflow-created Pods.

It should not be hard to identify Airflow-created pods, given the specific labels Airflow adds to the Pods it creates (https://github.com/apache/airflow/blob/2.0.1/airflow/kubernetes/pod_generator.py#L385)




airflow/cli/cli_parser.py
"List DAG runs given a DAG id. If state option is given, it will only search for all the "
            "dagruns with the given state. If no_backfill option is given, it will filter out all "
            "backfill dagruns for given dag id. If start_date is given, it will filter out all the "
            "dagruns that were executed before this date. If end_date is given, it will filter out "
            "all the dagruns that were executed after this date. "
        ),
        func=lazy_load_command('airflow.cli.commands.dag_command.dag_list_dag_runs'),
        args=(
            ARG_DAG_ID_OPT,
            ARG_NO_BACKFILL,
            ARG_STATE,
            ARG_OUTPUT,
            ARG_VERBOSE,
            ARG_START_DATE,
            ARG_END_DATE,
        ),
    ),
    ActionCommand(
        name='list-jobs',
        help="List the jobs",
        func=lazy_load_command('airflow.cli.commands.dag_command.dag_list_jobs'),
        args=(ARG_DAG_ID_OPT, ARG_STATE, ARG_LIMIT, ARG_OUTPUT, ARG_VERBOSE),
    ),
    ActionCommand(
        name='state',
        help="Get the status of a dag run",
        func=lazy_load_command('airflow.cli.commands.dag_command.dag_state'),
        args=(ARG_DAG_ID, ARG_EXECUTION_DATE, ARG_SUBDIR),
    ),
    ActionCommand(