Found while testing MDLQA-5538

When the File limit for picture and file fields are set to course upload limit, file uploads fail with the message: The file is larger than the space remaining in this area.

Steps to reproduce:

As a teacher:
Create a database activity using the default settings.
Add a file field named "file" be sure that the maximum size is set to course upload limit
Add a picture field named "photo" be sure that the maximum size is set to course upload limit

As a student:
Navigate to the database activity and click "Add entry"
Attempt to upload a file to the field named "file" be sure that the file is smaller than the course upload limit (For my testing I used a 5K file and the course limit was set to 2MB)
save these changes

Expected result: the file should upload successfully:
Actual result: The following error is displayed: The file is larger than the space remaining in this area.

Repeat the process with the field named Photo.

Note this issue does not appear if the file limit is NOT set to "Course upload limit"