Match CupertinoPageTransitionsBuilder animation duration to CupertinoPageRoute (#160241)

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The recent changes have made it possible to customize the duration in
PageTransitionsBuilder, so I have adjusted
CupertinoPageTransitionsBuilder's transition duration to
CupertinoPageRoute.

related issue: #29068

| Before | After | Native |
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packages/flutter/lib/src/cupertino/route.dart

@@ -148,9 +148,13 @@ mixin CupertinoRouteTransitionMixin<T> on PageRoute<T> {
     super.didChangePrevious(previousRoute);
   }
 
+  /// The duration of the page transition.
+  ///
+  /// A relatively rigorous eyeball estimation.
+  static const Duration kTransitionDuration = Duration(milliseconds: 500);
+
   @override
-  // A relatively rigorous eyeball estimation.
-  Duration get transitionDuration => const Duration(milliseconds: 500);
+  Duration get transitionDuration => kTransitionDuration;
 
   @override
   Color? get barrierColor => fullscreenDialog ? null : _kCupertinoPageTransitionBarrierColor;

packages/flutter/lib/src/material/page_transitions_theme.dart

@@ -1019,6 +1019,9 @@ class CupertinoPageTransitionsBuilder extends PageTransitionsBuilder {
   /// Constructs a page transition animation that matches the iOS transition.
   const CupertinoPageTransitionsBuilder();
 
+  @override
+  Duration get transitionDuration => CupertinoRouteTransitionMixin.kTransitionDuration;
+
   @override
   DelegatedTransitionBuilder? get delegatedTransition =>
       CupertinoPageTransition.delegatedTransition;

packages/flutter/test/material/page_transitions_theme_test.dart

@@ -286,6 +286,48 @@ void main() {
     variant: TargetPlatformVariant.only(TargetPlatform.android),
   );
 
+  testWidgets(
+    'CupertinoPageTransitionsBuilder default duration is 500ms',
+    (WidgetTester tester) async {
+      final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
+        '/':
+            (BuildContext context) => Material(
+              child: TextButton(
+                child: const Text('push'),
+                onPressed: () {
+                  Navigator.of(context).pushNamed('/b');
+                },
+              ),
+            ),
+        '/b': (BuildContext context) => const Text('page b'),
+      };
+
+      await tester.pumpWidget(
+        MaterialApp(
+          theme: ThemeData(
+            pageTransitionsTheme: const PageTransitionsTheme(
+              builders: <TargetPlatform, PageTransitionsBuilder>{
+                TargetPlatform.iOS: CupertinoPageTransitionsBuilder(),
+              },
+            ),
+          ),
+          routes: routes,
+        ),
+      );
+
+      expect(find.byType(CupertinoPageTransition), findsOneWidget);
+
+      await tester.tap(find.text('push'));
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 499));
+      expect(tester.hasRunningAnimations, isTrue);
+
+      await tester.pump(const Duration(milliseconds: 10));
+      expect(tester.hasRunningAnimations, isFalse);
+    },
+    variant: TargetPlatformVariant.only(TargetPlatform.iOS),
+  );
+
   testWidgets(
     'Animation duration changes accordingly when page transition builder changes',
     (WidgetTester tester) async {

packages/flutter/test/widgets/heroes_test.dart

@@ -1975,7 +1975,7 @@ Future<void> main() async {
 
       await tester.tap(find.text('two'));
       await tester.pump();
-      await tester.pump(const Duration(milliseconds: 500));
+      await tester.pump(const Duration(milliseconds: 501));
 
       expect(find.byKey(firstKey), findsNothing);
       expect(find.byKey(secondKey), isOnstage);
@@ -2016,7 +2016,7 @@ Future<void> main() async {
 
       await tester.tap(find.text('two'));
       await tester.pump();
-      await tester.pump(const Duration(milliseconds: 500));
+      await tester.pump(const Duration(milliseconds: 501));
 
       expect(find.byKey(firstKey), findsNothing);
       expect(find.byKey(secondKey), isOnstage);