* and stop setting default values in python operator code, so defaults can be set at the server side.

This issue is just for the PR and questions from maintainers. 
tests/providers/yandex/operators/test_yandexcloud_dataproc.py
args=[
                '-mapper',
                'mapper.py',
                '-reducer',
                'reducer.py',
                '-numReduceTasks',
                '1',
                '-input',
                's3a://some-in-bucket/jobs/sources/data/cities500.txt.bz2',
                '-output',
                's3a://some-out-bucket/dataproc/job/results',
            ],
            properties={
                'yarn.app.mapreduce.am.resource.mb': '2048',
                'yarn.app.mapreduce.am.command-opts': '-Xmx2048m',
                'mapreduce.job.maps': '6',
            },
        )
        context = {'task_instance': MagicMock()}
        context['task_instance'].xcom_pull.return_value = 'my_cluster_id'
        operator.execute(context)
        context['task_instance'].xcom_pull.assert_has_calls(
            [
                call(key='cluster_id'),
                call(key='yandexcloud_connection_id'),
            ]
        )
        create_mapreduce_job_mock.assert_called_once_with(
            archive_uris=None,
            args=[