feat: postgres dialect - review fixes

Author: ansh0l

google/cloud/spanner_v1/database.py

@@ -125,6 +125,11 @@ class Database(object):
  If a dict is provided, it must be of the same form as either of the protobuf
  messages :class:`~google.cloud.spanner_admin_database_v1.types.EncryptionConfig`
  or :class:`~google.cloud.spanner_admin_database_v1.types.RestoreDatabaseEncryptionConfig`
+ :type database_dialect:
+ :class:`~google.cloud.spanner_admin_database_v1.types.DatabaseDialect`
+ :param database_dialect:
+ (Optional) database dialect for the database
+
  """
 
  _spanner_api = None

tests/system/test_session_api.py

@@ -1983,7 +1983,7 @@ def test_execute_sql_w_numeric_bindings(not_emulator, not_postgres, sessions_dat
  )
 
 
-def test_execute_sql_w_json_bindings(not_emulator, sessions_database):
+def test_execute_sql_w_json_bindings(not_emulator, sessions_database, database_dialect):
  _bind_test_helper(
  sessions_database,
  database_dialect,