## Description
This PRs changes the default value transit mode for key event simulation.
The default transit mode for key event simulation is currently `KeyDataTransitMode.rawKeyData` while on the framework side `KeyDataTransitMode.keyDataThenRawKeyData` is the preferred transit mode.
`KeyDataTransitMode.keyDataThenRawKeyData` is more accurate and can help detect issues.
For instance the following test will fail with `KeyDataTransitMode.rawKeyData` because raw keyboard logic for modifier keys is less accurate:
```dart
testWidgets('Press control left once', (WidgetTester tester) async {
debugKeyEventSimulatorTransitModeOverride = KeyDataTransitMode.keyDataThenRawKeyData;
final List<KeyEvent> events = <KeyEvent>[];
final FocusNode focusNode = FocusNode();
addTearDown(focusNode.dispose);
await tester.pumpWidget(
Focus(
focusNode: focusNode,
autofocus: true,
onKeyEvent: (_, KeyEvent event) {
events.add(event);
return KeyEventResult.handled;
},
child: Container(),
),
);
await simulateKeyDownEvent(LogicalKeyboardKey.controlLeft);
// This will fail when transit mode is KeyDataTransitMode.rawKeyData
// because a down event for controlRight is synthesized.
expect(events.length, 1);
debugKeyEventSimulatorTransitModeOverride = null;
});
```
And the following this test is ok with `KeyDataTransitMode.rawKeyData` but rightly fails with `KeyDataTransitMode.keyDataThenRawKeyData`:
```dart
testWidgets('Simulates consecutive key down events', (WidgetTester tester) async {
debugKeyEventSimulatorTransitModeOverride = KeyDataTransitMode.rawKeyData;
// Simulating several key down events without key up in between is tolerated
// when transit mode is KeyDataTransitMode.rawKeyData, it will trigger an
// assert on KeyDataTransitMode.keyDataThenRawKeyData.
await simulateKeyDownEvent(LogicalKeyboardKey.arrowDown);
await simulateKeyDownEvent(LogicalKeyboardKey.arrowDown);
debugKeyEventSimulatorTransitModeOverride = null;
});
```
## Related Issue
Related to https://github.com/flutter/flutter/issues/143845
## Tests
Adds two tests.
8ade81fb20