cleanup(storage): add newline at end of file (#9605)

Author: devbww

google/cloud/storage/internal/group_options_test.cc

@@ -73,4 +73,4 @@ TEST(MakeOptionSpanTest, Declaration) {
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
 }  // namespace storage
 }  // namespace cloud
-}  // namespace google
+}  // namespace google