Disabled loading buttons (like below) do not render html <button> with disabled property.

<Button disabled loading content="loading" />

Environment Information

• Package version(s): @fluentui/react-northstar at 0.52.0
• Browser and OS versions: All

Please provide a reproduction of the bug in a codepen:

https://codesandbox.io/s/q083f?module=/example.js&file=/example.js

Actual behavior:

The rendered <button> element does not have disabled property

Expected behavior:

The rendered <button> element should have disabled property

Priorities and help requested:

Are you willing to submit a PR to fix? No

Requested priority: Normal

Products/sites affected: NA