Upstream Katello PR: https://github.com/Katello/katello/pull/6217

Note: the permissions needed to perform incremental update include:

- Organization => view_organizations

- Lifecycle Environment => view_lifecycle_environments, promote_or_remove_content_views_to_environments

- Content Views => view_content_views, publish_content_views, promote_or_remove_content_views

- Host => view_hosts, edit_hosts

Verified in Satellite 6.2.3 Snap 3.

Setup a role with the permissions outlined in #6. See attached.
Created two content views, one without errata filters, one with.
Registered a host to the filtered content view.
Switched to testuser (with custom permissions role)
Applied errata to host, incrementally updating the filtered content view (see attached for verification)

Created attachment 1210249 [details]
custom role

Created attachment 1210250 [details]
verification screenshot

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2016:2108