message: Ensure X/Y controls are updated when default launch pos selected
  Ensures the X & Y XAML controls are updated when the default launch position checkbox is toggled.
  References
diff: @@ -115,7 +115,7 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
  InitialPosX(NAN);
  InitialPosY(NAN);
  }
  - _NotifyChanges(L"UseDefaultLaunchPosition", L"LaunchParametersCurrentValue");
  + _NotifyChanges(L"UseDefaultLaunchPosition", L"LaunchParametersCurrentValue", L"InitialPosX", L"InitialPosY");
  }
  bool LaunchViewModel::UseDefaultLaunchPosition()
  