Activities include course limit for files even when it exceedes the site limit

The assignment, forum and workshop activities add the course limit to the list of allowed file sizes, even when this filesize is greater than the site limit.

Replication steps:

1. Log in as admin
2. Set the site file limit to something high (or server limit) at Settings > Site admin > Security > Site policies > Maximum uploaded file size (maxbytes)
3. Go to a course (or create one)
4. Edit the settings for the course and set the course file limit to the site limit
5. Go back to the site limit and reduce it to something lower, eg 2MB.
6. Go back to the course and edit the settings
7. Note the list of options for the file limit (it goes up to the site limit now), but this is not the value stored in the DB
8. Do not save the course settings (if you do, you need to start again)
9. Go back to the course page and add or edit an assignment activity
10. Note the list of options for the file limit
11. Add a forum and workshop activity and note the list of file size options there also

Expected result: The activity file limits should only go up to the site limit

Actual result: The course limit saved in the DB is included in the lists

This is happening in the settings pages for these activities, not in the library function which returns the list of allowed file sizes. The settings pages should check that the course limit is valid before adding it to the list of filesizes.

It should be noted that even when the activities limit is greater than the site limit, the site limit is still applied when students upload files.

I checked the Database activity and other modules and they do not appear to add the course limit to the list of file sizes.