style: reformat Dataflow API messages and test code for PEP 8 compliance

Author: bambadiouf1

sdks/python/apache_beam/runners/dataflow/internal/apiclient_test.py

@@ -622,8 +622,7 @@ def test_disk_provisioning_options(self):
                                 pipeline_options,
                                 '2.0.0',
                                 FAKE_PIPELINE_URL)
-    self.assertEqual(
-        env.proto.workerPools[0].diskProvisionedIops, 4000)
+    self.assertEqual(env.proto.workerPools[0].diskProvisionedIops, 4000)
     self.assertEqual(
         env.proto.workerPools[0].diskProvisionedThroughputMibps, 200)