Attach (recommended) or Link to PDF file here:
[output.pdf](https://github.com/mozilla/pdf.js/files/6374987/output.pdf)

Configuration:
- Web browser and its version: Firefox 88.0
- Operating system and its version: macOS Big Sur 11.2.3 (20D91)
- PDF.js version: 2.8.243
- Is a browser extension: no/Firefox built-in

Steps to reproduce the problem:
1.  add Ink-Annotations to a pdf (i use https://github.com/highkite/pdfAnnotate, Annotations with appearance streams are shown correctly)
2. open output file in firefox

What is the expected behavior? 
The annotations should be visible.
![Bildschirmfoto 2021-04-26 um 09 15 48](https://user-images.githubusercontent.com/33630884/116043809-6a020f80-a670-11eb-973c-6f2df3dae532.png)

What went wrong? 
The annotations are added to the dom but invisible.
![Bildschirmfoto 2021-04-26 um 09 18 26](https://user-images.githubusercontent.com/33630884/116043867-7e460c80-a670-11eb-964d-0cc2c6dbfb61.png)

Tested successfull with FoxitReader, AcrobatReader, Chrome and Safari.
};
    if (params.collectFields) {
      
      
      
      const kids = dict.get("Kids");
      if (Array.isArray(kids)) {
        const kidIds = [];
        for (const kid of kids) {
          if (isRef(kid)) {
            kidIds.push(kid.toString());
          }
        }
        if (kidIds.length !== 0) {
          this.data.kidIds = kidIds;
        }
      }
      this.data.actions = collectActions(
        params.xref,
        dict,
        AnnotationActionEventType
      );
      this.data.fieldName = this._constructFieldName(dict);
    }
    this._fallbackFontDict = null;
  }
  /**
   * @private
   */
  _hasFlag(flags, flag) {