* 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/hooks/test_yandexcloud_dataproc.py
'yarn.app.mapreduce.am.command-opts': '-Xmx2048m',
                'mapreduce.job.maps': '6',
            },
        )
        assert create_operation_mock.called
    @patch('yandexcloud.SDK.create_operation_and_get_result')
    def test_create_spark_job_hook(self, create_operation_mock):
        self._init_hook()
        self.hook.client.create_spark_job(
            archive_uris=['s3a://some-in-bucket/jobs/sources/data/country-codes.csv.zip'],
            args=[
                's3a://some-in-bucket/jobs/sources/data/cities500.txt.bz2',
                's3a://some-out-bucket/dataproc/job/results/${{JOB_ID}}',
            ],
            cluster_id='my_cluster_id',
            file_uris=['s3a://some-in-bucket/jobs/sources/data/config.json'],
            jar_file_uris=[
                's3a://some-in-bucket/jobs/sources/java/icu4j-61.1.jar',
                's3a://some-in-bucket/jobs/sources/java/commons-lang-2.6.jar',
                's3a://some-in-bucket/jobs/sources/java/opencsv-4.1.jar',
                's3a://some-in-bucket/jobs/sources/java/json-20190722.jar',
            ],
            main_class='ru.yandex.cloud.dataproc.examples.PopulationSparkJob',
            main_jar_file_uri='s3a://data-proc-public/jobs/sources/java/dataproc-examples-1.0.jar',
            name='Spark job',
            properties={'spark.submit.deployMode': 'cluster'},
        )
        assert create_operation_mock.called
    @patch('yandexcloud.SDK.create_operation_and_get_result')
    def test_create_pyspark_job_hook(self, create_operation_mock):