address gemeni review comment and lint issue

Author: derrickaw

sdks/python/apache_beam/yaml/tests/create.yaml

@@ -163,7 +163,7 @@ pipelines:
             language: python
             fields: 
               sdk: "element.sdk"
-              year: "element.year"   
+              year: "element.year"
         - type: AssertEqual
           input: MapToFields
           config:

sdks/python/apache_beam/yaml/yaml_transform.py

@@ -40,8 +40,8 @@
 from apache_beam.yaml import yaml_provider
 from apache_beam.yaml import yaml_utils
 from apache_beam.yaml.yaml_combine import normalize_combine
-from apache_beam.yaml.yaml_mapping import normalize_mapping
 from apache_beam.yaml.yaml_mapping import Validate
+from apache_beam.yaml.yaml_mapping import normalize_mapping
 from apache_beam.yaml.yaml_mapping import validate_generic_expressions
 from apache_beam.yaml.yaml_utils import SafeLineLoader