Describe the bug

The description for a b-form-group containing a b-form-radio-group is not accessible to the ChromeVox screen reader.

Steps to reproduce the bug

1. Activate ChromeVox (Ctrl+Alt+Z)
2. Go to https://jsfiddle.net/qw394szo/1/
3. Use the tab key to select the radio button group
4. ChromeVox reads "option a, radio button unselected; 1 of 2; Radio button group; Label; Form;"

Expected behavior

ChromeVox should have read "option a, radio button unselected; 1 of 2; Radio button group; Label; Form; Description"

Versions

Libraries:

• BootstrapVue: 2.19.0
• Bootstrap: 4.5.3
• Vue: 2.6.12

Environment:

• Device: Chromebook
• OS: ChromeOS
• Browser: Chrome
• Version: 86

Demo link

https://jsfiddle.net/qw394szo/1/

Additional context

Similar to #5918 (comment)