Updates flutter/test/gestures to no longer reference TestWindow (flutter#122327)

Updates `flutter/test/gestures` to no longer reference `TestWindow`

Author: pdblasi-google

packages/flutter/test/gestures/gesture_config_regression_test.dart

@@ -90,7 +90,9 @@ class NestedDraggableCase extends StatelessWidget {
 
 void main() {
   testWidgets('Scroll Views get the same ScrollConfiguration as GestureDetectors', (WidgetTester tester) async {
-    tester.binding.window.gestureSettingsTestValue = const ui.GestureSettings(physicalTouchSlop: 4);
+    tester.view.gestureSettings = const ui.GestureSettings(physicalTouchSlop: 4);
+    addTearDown(tester.view.reset);
+
     final TestResult result = TestResult();
 
     await tester.pumpWidget(MaterialApp(
@@ -108,11 +110,11 @@ void main() {
 
    expect(result.dragStarted, true);
    expect(result.dragUpdate, true);
-   tester.binding.window.clearGestureSettingsTestValue();
   });
 
   testWidgets('Scroll Views get the same ScrollConfiguration as Draggables', (WidgetTester tester) async {
-    tester.binding.window.gestureSettingsTestValue = const ui.GestureSettings(physicalTouchSlop: 4);
+    tester.view.gestureSettings = const ui.GestureSettings(physicalTouchSlop: 4);
+    addTearDown(tester.view.reset);
 
     final TestResult result = TestResult();
 
@@ -131,6 +133,5 @@ void main() {
 
    expect(result.dragStarted, true);
    expect(result.dragUpdate, true);
-   tester.binding.window.clearGestureSettingsTestValue();
   });
 }