* 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
self._init_hook()
        self.hook.client.create_mapreduce_job(
            archive_uris=None,
            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',
            ],
            cluster_id='my_cluster_id',
            file_uris=[
                's3a://some-in-bucket/jobs/sources/mapreduce-001/mapper.py',
                's3a://some-in-bucket/jobs/sources/mapreduce-001/reducer.py',
            ],
            jar_file_uris=None,
            main_class='org.apache.hadoop.streaming.HadoopStreaming',
            main_jar_file_uri=None,
            name='Mapreduce job',
            properties={
                'yarn.app.mapreduce.am.resource.mb': '2048',