Adding a user as a member to a discussion item doesn't make the discussion show up in that user's discussion library

Here are the steps taken to reproduce:

- Log in with user A.
- Create a new discussion (visibility doesn't matter, used public)
- Open the clip, open the manage access widget, add user B as a viewer (or manager) to the discussion and save the changes.
- Log in with user B
- Observe that the user gets a notification and activity for the actions but when navigation to the discussion library the item will not be in there.

Note: when user A shares the discussion with user B (through the share pop-over) the discussion shows up in user B's discussion library.