Change SizeChangedEvent routing strategy to direct
Change SizeChangedEvent routing strategy to direct

This matches WPF and making it bubble was a mistake.

AvaloniaUI/Avalonia,AvaloniaUI/Avalonia,AvaloniaUI/Avalonia,AvaloniaUI/Avalonia,AvaloniaUI/Avalonia,AvaloniaUI/Avalonia,AvaloniaUI/Avalonia