fix failure to forward to collection edit after create for PcdmCollection

[elrayle]

Description

When a collection is created with Hyrax.config.collection_model = 'Hyrax::PcdmCollection', the page does not forward to the collection edit page after saving the new collection.

Cause

The valkyrie_create method did not call after_create. The after_create method is what performed the forward to the edit page.

Solution

Update valkyrie_create to call after_create if saving is successful. The after_create method was also updated to perform some steps only when @collection.is_a? ActiveFedora::Base because those steps were already performed by valkyrie_create.

@samvera/hyrax-code-reviewers