Hi There,
This behavior is same in earlier version as well. One way is to put "Included Resource Paths & Content Types" like shown below however it is very restrictive way as regular expression does not work and path prefix has to be put up.

I suggest you just uncheck the all resources and handle the same at apache level. So basically all the assets will be shown in-browser for streaming and then whenever you want to override this behavior, do that at dispatcher layer by adding for example below snippet:
<FilesMatch "\.pdf$">
Header set Content-Disposition attachment
</FilesMatch>