Crash in KeyboardEventHandler when no corewindow

[asklar]

• run template app against winui 3
• hover over something, press the alt key
• we crash when dereferencing a null corewindow:

note that there are more usages of corewindow in this file that we need to provide alternatives when no corewindow is available

react-native-windows/vnext/Microsoft.ReactNative/Views/KeyboardEventHandler.cpp

Lines 200 to 207 in 003602b

	void UpdateModifiedKeyStatusTo(T &event) {
	auto const &coreWindow = winrt::CoreWindow::GetForCurrentThread();
	event.altKey = KeyboardHelper::IsModifiedKeyPressed(coreWindow, winrt::Windows::System::VirtualKey::Menu);
	event.shiftKey = KeyboardHelper::IsModifiedKeyPressed(coreWindow, winrt::Windows::System::VirtualKey::Shift);
	event.metaKey = KeyboardHelper::IsModifiedKeyPressed(coreWindow, winrt::Windows::System::VirtualKey::LeftWindows) ||
	KeyboardHelper::IsModifiedKeyPressed(coreWindow, winrt::Windows::System::VirtualKey::RightWindows);
	event.ctrlKey = KeyboardHelper::IsModifiedKeyPressed(coreWindow, winrt::Windows::System::VirtualKey::Control);
	event.capLocked = KeyboardHelper::IsModifiedKeyLocked(coreWindow, winrt::Windows::System::VirtualKey::CapitalLock);

[asklar]

will need to try this out in winappsdk 1.0 once we update
@AgneLukoseviciute fyi

[jonthysell]

@TatianaKapos Do you think this will make 0.69 or should it be moved to 0.70?

[lyahdav]

Heads up: I have a fix for this. Will put up PR shortly.