Keep Editor window alive during VR Preview

PlayLevel.cpp

if (bUseVRPreviewForPlayWorld && GEngine->HMDDevice.IsValid())
{
	GEngine->HMDDevice->EnableStereo(true);

	// minimize the root window to provide max performance for the preview.
	TSharedPtr<SWindow> RootWindow = FGlobalTabmanager::Get()->GetRootWindow();
	if (RootWindow.IsValid())
	{
	  //////////////////////////////
    //TODO: ikrimae: Pipe disabling this based on a config variable. So far hasn't crashed the editor but need stability testing & also it's a perf hit
		//RootWindow->Minimize();
		//////////////////////////////
	}
}