The view_set parameter on AccessPolicy is not namespacing plugins
We need to use another deterninant here because e.g. PackageViewSet will appear in multiple plugins.
In: ContainerDistributionViewSet.view_name() Out: 'distributions-container/container'
would do the job.
If no plugin is using AccessPolicy by now, we can just switch the lookup here. Otherwise we'd need to be very careful with deprecating it, because a failed lookup will result in "500" errors.