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`.
optionElement.textContent = option.displayValue;
      optionElement.value = option.exportValue;
      if (this.data.fieldValue.includes(option.exportValue)) {
        optionElement.setAttribute("selected", true);
      }
      selectElement.appendChild(optionElement);
    }
    const getValue = (event, isExport) => {
      const name = isExport ? "value" : "textContent";
      const options = event.target.options;
      if (!event.target.multiple) {
        return options.selectedIndex === -1
          ? null
          : options[options.selectedIndex][name];
      }
      return Array.prototype.filter
        .call(options, option => option.selected)
        .map(option => option[name]);
    };
    const getItems = event => {
      const options = event.target.options;
      return Array.prototype.map.call(options, option => {
        return { displayValue: option.textContent, exportValue: option.value };
      });
    };
    if (this.enableScripting && this.hasJSActions) {
      selectElement.addEventListener("updatefromsandbox", event => {
        const { detail } = event;
        const actions = {
          value() {