[EuiSuperDatePicker][SCREEN READER]: Adding a live region to the time range popover so changes are announced by assistive technologies

[1Copenut]

Steps to reproduce

1. Open a Kibana sample instance
2. Start a screen reader like VoiceOver or NVDA
3. Click "Last 7 days" or tab to this input and press ENTER
4. Verify the Relative tab is opened under date range popover
5. Adjust the time spinner from 1 to 2, 3, 4, etc.
6. Verify the readOnly date range below the input is changing, but no change is read aloud by the screen reader

Actual Result

• Updated date range is not read aloud by screen readers

Expected Result

• Updated date range is read aloud by screen readers

Meta Issue

• The EUI FormControlLayout allows users to spread props onto the containing DIV. We can add the live region to the Super Date Picker in two sub-components and it'll update when users make changes:

! absolute_tab.tsx#126
! src > components > date_picker > super_date_picker > date_popover > absolute_tab.tsx

<EuiFieldText
+ aria-atomic="true"
+ aria-live="polite"
+ aria-relevant="additions text"
  ...
/>

! relative_tab.tsx#204
! src > components > date_picker > super_date_picker > date_popover > relative_tab.tsx

<EuiFieldText
+ aria-atomic="true"
+ aria-live="polite"
+ aria-relevant="additions text"
  ...
/>

~~Kibana Version:~~ ~~v8.0.0~~

OS: MacOS Big Sur

Browser: Chrome, Safari

Screen reader: [if relevant] VoiceOver

Relevant WCAG Criteria:

• Understanding Success Criterion 4.1.2: Name, Role, Value - Level A
• Understanding Success Criterion 4.1.3: Status Messages - Level AA

[elasticmachine]

Pinging @elastic/kibana-accessibility (Project:Accessibility)

[github-actions[bot]]

👋 Hey there. This issue hasn't had any activity for 180 days. We'll automatically close it if that trend continues for another week. If you feel this issue is still valid and needs attention please let us know with a comment.

[github-actions[bot]]

👋 Hi there - this issue hasn't had any activity in 6 months. If the EUI team has not explicitly expressed that this is something on our roadmap, it's unlikely that we'll pick this issue up. We would sincerely appreciate a PR/community contribution if this is something that matters to you! If not, and there is no further activity on this issue for another 6 months (i.e. it's stale for over a year), the issue will be auto-closed.

[github-actions[bot]]

❌ Per our previous message, this issue is auto-closing after having been open and inactive for a year. If you strongly feel this is still a high-priority issue, or are interested in contributing, please leave a comment or open a new issue linking to this one for context.