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`.
const color = detail.strokeColor;
              event.target.style.color = ColorConverters[`${color[0]}_HTML`](
                color.slice(1)
              );
            },
          };
          Object.keys(detail)
            .filter(name => name in actions)
            .forEach(name => actions[name]());
        });
        
        
        element.addEventListener("keydown", event => {
          elementData.beforeInputValue = event.target.value;
          
          
          let commitKey = -1;
          if (event.key === "Escape") {
            commitKey = 0;
          } else if (event.key === "Enter") {
            commitKey = 2;
          } else if (event.key === "Tab") {
            commitKey = 3;
          }
          if (commitKey === -1) {
            return;
          }