code: @VisibleForTesting
    static <T> Iterable<T> getCandidatesViaHardCoded(Class<T> klass, Iterable<Class<?>> hardcoded) {
      List<T> list = new ArrayList<>();
      for (Class<?> candidate : hardcoded) {
        list.add(create(klass, candidate));
      }
      return list;
    }
docs: Load providers from a hard-coded list. This avoids using getResource(), which has performance
  problems on Android (see https://github.com/grpc/grpc-java/issues/2037).