* 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. 
airflow/providers/yandex/example_dags/example_yandexcloud_dataproc.py
query='SELECT 1;',
    )
    create_hive_query_from_file = DataprocCreateHiveJobOperator(
        task_id='create_hive_query_from_file',
        query_file_uri='s3a://data-proc-public/jobs/sources/hive-001/main.sql',
        script_variables={
            'CITIES_URI': 's3a://data-proc-public/jobs/sources/hive-001/cities/',
            'COUNTRY_CODE': 'RU',
        },
    )
    create_mapreduce_job = DataprocCreateMapReduceJobOperator(
        task_id='create_mapreduce_job',
        main_class='org.apache.hadoop.streaming.HadoopStreaming',
        file_uris=[
            's3a://data-proc-public/jobs/sources/mapreduce-001/mapper.py',
            's3a://data-proc-public/jobs/sources/mapreduce-001/reducer.py',
        ],
        args=[
            '-mapper',
            'mapper.py',
            '-reducer',
            'reducer.py',
            '-numReduceTasks',
            '1',
            '-input',
            's3a://data-proc-public/jobs/sources/data/cities500.txt.bz2',
            '-output',
            f's3a://{S3_BUCKET_NAME_FOR_JOB_LOGS}/dataproc/job/results',
        ],
        properties={