public static byte[] marshallParcelableList(ArrayList<? extends Parcelable> parcelables) {
    Parcel parcel = Parcel.obtain();
    parcel.writeList(parcelables);
    parcel.setDataPosition(0);
    return parcel.marshall();
  }
Marshalls a list of {@link Parcelable} into parcel bytes for adding into an {@link Intent}
extras. Workaround for bug: https://code.google.com/p/android/issues/detail?id=6822
java/com/google/android/apps/authenticator/util/IntentUtils.java