Attach (recommended) or Link to PDF file here: [form-cms1500.pdf](https://github.com/mozilla/pdf.js/files/5670936/form-cms1500.pdf) (Original opened in Acrobat and checked one radio-button)
Original Source: https://www.cigna.com/static/www-cigna-com/docs/health-care-providers/form-cms1500.pdf

Configuration:
- Web browser and its version: FF 83.0
- Operating system and its version: Win 10 Pro
- PDF.js version: 2.7.355

Steps to reproduce the problem:
1. Open the PDF here: https://mozilla.github.io/pdf.js/web/viewer.html
2. See that all radio-buttons are checked, which is wrong.

What is the expected behavior? (add screenshot)
![grafik](https://user-images.githubusercontent.com/12390057/101734698-f72d3900-3ac0-11eb-817e-94ce276797e8.png)

What went wrong? (add screenshot)
![grafik](https://user-images.githubusercontent.com/12390057/101734712-fc8a8380-3ac0-11eb-833d-412243a7950c.png)

This radio-button field can be found in object `45 0 obj`.
if (!this.downloadManager) {
      warn("Download cannot be started due to unavailable download manager");
      return;
    }
    this.downloadManager.downloadData(this.content, this.filename, "");
  }
}
/**
 * @typedef {Object} AnnotationLayerParameters
 * @property {PageViewport} viewport
 * @property {HTMLDivElement} div
 * @property {Array} annotations
 * @property {PDFPage} page
 * @property {IPDFLinkService} linkService
 * @property {DownloadManager} downloadManager
 * @property {string} [imageResourcesPath] - Path for image resources, mainly
 *   for annotation icons. Include trailing slash.
 * @property {boolean} renderInteractiveForms
 * @property {boolean} [enableScripting] - Enable embedded script execution.
 * @property {boolean} [hasJSActions] - Some fields have JS actions.
 *   The default value is `false`.
 */
class AnnotationLayer {