code: @WorkerThread
    public static LottieResult<LottieComposition> fromJsonStringSync(String json, @Nullable String cacheKey) {
      return fromJsonReaderSync(new JsonReader(new StringReader(json)), cacheKey);
    }
docs: Return a LottieComposition for the specified raw json string.
  If loading from a file, it is preferable to use the InputStream or rawRes version.