Fix context menu button color on Android when textButtonTheme is set (#133271)

Fixes #133027

When setting a `textButtonTheme` it should not override the native context menu colors.

```dart
  theme: ThemeData(
    textButtonTheme: const TextButtonThemeData(
      style: ButtonStyle(
        backgroundColor: MaterialStatePropertyAll<Color>(
            Color(0xff05164d)), // blue color
      ),
    ),
  ),
```

Before|After
--|--
<img width="341" alt="Screenshot 2023-08-24 at 1 17 25 PM" src="https://github.com/flutter/flutter/assets/948037/30ea0ef8-b41a-4e1f-93a3-50fcd87ab2bf">|<img width="341" alt="Screenshot 2023-08-24 at 1 15 35 PM" src="https://github.com/flutter/flutter/assets/948037/5f59481c-aa5d-4850-aa4b-daa678e54044">

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

@@ -135,6 +135,12 @@ class TextSelectionToolbarTextButton extends StatelessWidget {
   static const Color _defaultForegroundColorLight = Color(0xff000000);
   static const Color _defaultForegroundColorDark = Color(0xffffffff);
 
+  // The background color is hardcoded to transparent by default so the buttons
+  // are the color of the container behind them. For example TextSelectionToolbar
+  // hardcodes the color value, and TextSelectionToolbarTextButtons that are its
+  // children become that color.
+  static const Color _defaultBackgroundColorTransparent = Color(0x00000000);
+
   static Color _getForegroundColor(ColorScheme colorScheme) {
     final bool isDefaultOnSurface = switch (colorScheme.brightness) {
       Brightness.light => identical(ThemeData().colorScheme.onSurface, colorScheme.onSurface),
@@ -154,6 +160,7 @@ class TextSelectionToolbarTextButton extends StatelessWidget {
     final ColorScheme colorScheme = Theme.of(context).colorScheme;
     return TextButton(
       style: TextButton.styleFrom(
+        backgroundColor: _defaultBackgroundColorTransparent,
         foregroundColor: _getForegroundColor(colorScheme),
         shape: const RoundedRectangleBorder(),
         minimumSize: const Size(kMinInteractiveDimension, kMinInteractiveDimension),

packages/flutter/test/material/text_selection_toolbar_text_button_test.dart

@@ -123,5 +123,72 @@ void main() {
         customForegroundColor,
       );
     });
+
+    testWidgetsWithLeakTracking('background color by default', (WidgetTester tester) async {
+      // Regression test for https://github.com/flutter/flutter/issues/133027
+      await tester.pumpWidget(
+        MaterialApp(
+          theme: ThemeData(
+            colorScheme: colorScheme,
+          ),
+          home: Scaffold(
+            body: Center(
+              child: TextSelectionToolbarTextButton(
+                padding: TextSelectionToolbarTextButton.getPadding(0, 1),
+                child: const Text('button'),
+              ),
+            ),
+          ),
+        ),
+      );
+
+      expect(find.byType(TextButton), findsOneWidget);
+
+      final TextButton textButton = tester.widget(find.byType(TextButton));
+      // The background color is hardcoded to transparent by default so the buttons
+      // are the color of the container behind them. For example TextSelectionToolbar
+      // hardcodes the color value, and TextSelectionToolbarTextButton that are its
+      // children should be that color.
+      expect(
+        textButton.style!.backgroundColor!.resolve(<MaterialState>{}),
+        Colors.transparent,
+      );
+    });
+
+    testWidgetsWithLeakTracking('textButtonTheme should not override default background color', (WidgetTester tester) async {
+      // Regression test for https://github.com/flutter/flutter/issues/133027
+      await tester.pumpWidget(
+        MaterialApp(
+          theme: ThemeData(
+            colorScheme: colorScheme,
+            textButtonTheme: const TextButtonThemeData(
+              style: ButtonStyle(
+                backgroundColor: MaterialStatePropertyAll<Color>(Colors.blue),
+              ),
+            ),
+          ),
+          home: Scaffold(
+            body: Center(
+              child: TextSelectionToolbarTextButton(
+                padding: TextSelectionToolbarTextButton.getPadding(0, 1),
+                child: const Text('button'),
+              ),
+            ),
+          ),
+        ),
+      );
+
+      expect(find.byType(TextButton), findsOneWidget);
+
+      final TextButton textButton = tester.widget(find.byType(TextButton));
+      // The background color is hardcoded to transparent by default so the buttons
+      // are the color of the container behind them. For example TextSelectionToolbar
+      // hardcodes the color value, and TextSelectionToolbarTextButton that are its
+      // children should be that color.
+      expect(
+        textButton.style!.backgroundColor!.resolve(<MaterialState>{}),
+        Colors.transparent,
+      );
+    });
   }
 }