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 (interiorColor) {
        interiorColor = getRgbColor(interiorColor);
        fillColor = interiorColor
          ? Array.from(interiorColor).map(c => c / 255)
          : null;
      }
      this._setDefaultAppearance({
        xref: parameters.xref,
        extra: `${this.borderStyle.width} w`,
        strokeColor,
        fillColor,
        pointsCallback: (buffer, points) => {
          const x = points[2].x + this.borderStyle.width / 2;
          const y = points[2].y + this.borderStyle.width / 2;
          const width = points[3].x - points[2].x - this.borderStyle.width;
          const height = points[1].y - points[3].y - this.borderStyle.width;
          buffer.push(`${x} ${y} ${width} ${height} re`);
          if (fillColor) {
            buffer.push("B");
          } else {
            buffer.push("S");
          }
          return [points[0].x, points[1].x, points[3].y, points[1].y];
        },
      });
    }
  }
}
class CircleAnnotation extends MarkupAnnotation {
  constructor(parameters) {