fix: default stream integration test failures due to production expected change (#791)

Author: yirutang

google-cloud-bigquerystorage/src/test/java/com/google/cloud/bigquery/storage/v1beta2/it/ITBigQueryWriteManualClientTest.java

@@ -352,8 +352,8 @@ public void testJsonStreamWriterBatchWriteWithDefaultStream()
  ApiFuture<AppendRowsResponse> response2 = jsonStreamWriter.append(jsonArr2, -1);
  LOG.info("Sending one more message");
  ApiFuture<AppendRowsResponse> response3 = jsonStreamWriter.append(jsonArr3, -1);
- assertEquals(1, response2.get().getAppendResult().getOffset().getValue());
- assertEquals(3, response3.get().getAppendResult().getOffset().getValue());
+ Assert.assertFalse(response2.get().getAppendResult().hasOffset());
+ Assert.assertFalse(response3.get().getAppendResult().hasOffset());
 
  TableResult result =
  bigquery.listTableData(