Resolve Cupertino textstyle in MaterialBasedCupertinoThemeData (flutter#167597)

Fixes flutter#146864. The overridden resolve was keeping the Cupertino text
styles from resolving their dynamic colors depending on the theme
brightness when in a MaterialApp in most cases. I *believe* that this
was to keep values from the Material theme from changing, but as far as
I can tell that shouldn't affect anything in the current state and that
is 6 year old code. Waiting to see if tests make me a liar.

Update: tests made me a liar.

Before (text should be showing):
<img width="423" alt="Screenshot 2025-04-22 at 1 58 53 PM"
src="https://github.com/user-attachments/assets/0aabf6cf-2c25-4446-8d12-69e745f26be0"
/>

After:
<img width="418" alt="Screenshot 2025-04-22 at 1 59 16 PM"
src="https://github.com/user-attachments/assets/ea9958bb-4470-4f16-b5ca-f149be1301b1"
/>


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we expect every widget to implement].
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- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
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[test-exempt].
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Author: MitchellGoodwin

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

@@ -3010,11 +3010,14 @@ class MaterialBasedCupertinoThemeData extends CupertinoThemeData {
 
   @override
   CupertinoThemeData resolveFrom(BuildContext context) {
-    // Only the cupertino override theme part will be resolved.
+    // Only the cupertino override theme part will be resolved, as well as the
+    // default text theme.
     // If the color comes from the material theme it's not resolved.
+    final NoDefaultCupertinoThemeData cupertinoOverrideThemeWithTextTheme = _cupertinoOverrideTheme
+        .copyWith(textTheme: textTheme);
     return MaterialBasedCupertinoThemeData._(
       _materialTheme,
-      _cupertinoOverrideTheme.resolveFrom(context),
+      cupertinoOverrideThemeWithTextTheme.resolveFrom(context),
     );
   }
 }

packages/flutter/test/material/theme_test.dart

@@ -758,6 +758,30 @@ void main() {
       expect(CupertinoTheme.brightnessOf(context!), Brightness.light);
     });
 
+    testWidgets('Cupertino widgets correctly get the right text theme in dark mode', (
+      WidgetTester tester,
+    ) async {
+      final GlobalKey textFieldKey = GlobalKey();
+      await tester.pumpWidget(
+        MaterialApp(
+          theme: ThemeData.dark(),
+          home: Scaffold(body: CupertinoTextField(key: textFieldKey)),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final EditableTextState state = tester.state<EditableTextState>(find.byType(EditableText));
+
+      // Default CupertinoTextStyle color is a CupertinoDynamicColor.
+      final CupertinoThemeData cupertinoThemeData = CupertinoTheme.of(textFieldKey.currentContext!);
+      expect(cupertinoThemeData.textTheme.textStyle.color, isA<CupertinoDynamicColor>());
+      final CupertinoDynamicColor themeTextStyleColor =
+          cupertinoThemeData.textTheme.textStyle.color! as CupertinoDynamicColor;
+
+      // The value of the textfield's color should resolve to the theme's dark color.
+      expect(state.widget.style.color?.value, equals(themeTextStyleColor.darkColor.value));
+    });
+
     testWidgets('Material2 - Can override material theme', (WidgetTester tester) async {
       final CupertinoThemeData themeM2 = await testTheme(
         tester,