Fix ExpansionTile double tap to collapse/expanded and expanded/collapsed states semantics announcements

[TahaTesser]

fixes #120650

code sample

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(useMaterial3: true),
      home: const Scaffold(
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              ExpansionTile(
                title: Text('Flutter Forward'),
                children: <Widget>[
                  FlutterLogo(size: 100),
                ],
              ),
              SizedBox(height: 20),
              ExpansionTile(
                initiallyExpanded: true,
                title: Text('Flutter Forward'),
                children: <Widget>[
                  FlutterLogo(size: 100),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}

Demo

telegram-cloud-document-5-6334536656577628266.mp4

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• I read the Contributor Guide and followed the process outlined there for submitting PRs.
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• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

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[chunhtai]

Double checked with google internal a11y guideline and looks like this is also required for Android

1.4
Consider providing accessibility hints, especially in cases where additional detail may be helpful in explaining a click or long-click action. This is accomplished by overriding a standard accessibility action with a custom label, which will be appended to TalkBack’s feedback after the View’s content is spoken.

For example, if clicking on a card expands its contents to show more detail, but this isn’t conveyed in TalkBack’s output because the card contains other text, applying an accessibility hint as follows would result in TalkBack appending “Double tap to expand for more details.”, which provides a more polished user experience.

For iOS, we should add a SemanticsProperties.hint. The onTapHint does not work on iOS.
https://developer.apple.com/library/archive/documentation/UserExperience/Conceptual/iPhoneAccessibility/Making_Application_Accessible/Making_Application_Accessible.html#//apple_ref/doc/uid/TP40008785-CH102-SW6

[gspencergoog]

[TahaTesser]

@chunhtai
Updated the PR for the onTapHint label, however for iOS, there is no hint for the list tile or related widgets such as the expansion tile so I want to fix the list tile and other widgets together in a separate PR.

(updated demo video)

[chunhtai]

LGTM