How to stop Windows 10 from installing Candy Crush and Disney Magic Kingdom?

It seems like the problem got fixed in Windows 10 patch KB4345421. After uninstalling the apps today, they finally got removed.

Now, there's one odd thing about KB4345421: It was already installed on the day the original question was posted. Meanwhile it got installed two more times. The last installation of the patch (one day after the question was posted) seem to have finally fixed the issue. So if you suffer from the same issue, try to uninstall and reinstall KB4345421.