DAM Preview module not compatible with Magnolia 6.x

Steps to reproduce

1.  Visit https://docs.magnolia-cms.com/product-docs/6.2/Modules/List-of-modules/Digital-Asset-Management-module/DAM-Preview-module.html#_installing_with_maven
2. Add the module
3. Add pdf to dam app
4. See no PDF previews
5. Check config workspace to find the generators to be added to the config for the old configuration

Expected results

Expected generators to be registered and picked up to see previews of PDFs in DAM app. (Seems that info.magnolia.ui.contentapp.preview.JcrPreviewProvider does already provide for video and audio).

Actual results

Nothing changes 

Workaround

N/a however I would suggest either updating support for PDF in te future or remove the aformentioned documentation page from the docs.
Using the legacy asset app.

Development notes

Works in legacy assets app but not in the new dam app.