fix(material/datepicker): datepicker doesn't announce newly selected range in firefox

[essjay05]

trafficstars

Fixes a bug in the Angular Material component where when the selected year range is updated by moving forward to the next range or by moving to the previous range the screenreader announces the original date range rather than the newly selected date range. This is because the label class was removing the updated value from the Firefox accessibility tree.

Fixes #28360

[essjay05]

Before screencast: https://screencast.googleplex.com/cast/NjA1Mzg0MjEyMTY1NDI3MnxkYjE1OThkMy01MQ

After screencast: https://screencast.googleplex.com/cast/NTkyMTk0Njc3OTc3OTA3MnxhYWIxYjI3ZS1kMg https://screencast.googleplex.com/cast/NTUxMTYzMzEwMjE3NjI1NnxjYTIzZjYzMy01OQ

Note: tested successful description updates after changes on Safari (VoiceOver), Chrome (VoiceOver), Firefox (VoiceOver), Firefox (NVDA).

[essjay05]

Hello, it would be good to have a code comment explaining why the label is included in a11y tree.

Could you file an issue report on Firefox for this? @essjay05 looked together and were unable to make a minimal reproduction. We can use our Stackblitz environment to create a reproduction for the issue report. Out Stackblitz template is at https://stackblitz.com/fork/components-issue

Sounds good. Will add the note and file an issue report in Firefox.

[github-actions[bot]]

Deployed dev-app for 62f5a680c501a2725165a04cbff693f854f78a36 to: https://ng-dev-previews-comp--pr-angular-components-28529-dev-s03a4tjk.web.app

Note: As new commits are pushed to this pull request, this link is updated after the preview is rebuilt.

[angular-automatic-lock-bot[bot]]

This issue has been automatically locked due to inactivity. Please file a new issue if you are encountering a similar or related problem.

Read more about our automatic conversation locking policy.

_{This action has been performed automatically by a bot.}