Graded download issues

[CodeWithEmad]

This is a duplicate of hastexo/tutor-contrib-s3#77

Hi. I noticed a couple of issues related to GRADES_DOWNLOAD.
There's a section in the instructor tab of each course, where instructors can download grades in a CSV format.
Inside lms/djangoapps/instructor_task/models.py, where we create a DjangoStorageReportStore, it needs these values from the config, otherwise will fail:

• STORAGE_TYPE
• BUCKET
• ROOT_PATH
• CUSTOM_DOMAIN (if exists)

https://github.com/openedx/edx-platform/blob/f3f160f4f20f7bbde45fe0d48ac9626a694afb93/lms/djangoapps/instructor_task/models.py#L230-L242

Oddly, it's not reading them from AWS_S3_ configs.

In the plugin, just a bucket_name and a location kwargs are overridden.

GRADES_DOWNLOAD["STORAGE_KWARGS"] = {"location": GRADES_DOWNLOAD["STORAGE_KWARGS"]["location"].lstrip("/")}
GRADES_DOWNLOAD["STORAGE_KWARGS"]["bucket_name"] = "{{ S3_GRADE_BUCKET }}"

Note that I didn't use the plugin, but just used GRADES_DOWNLOAD config mentioned above and it didn't work.
If this is a valid issue, I would like to work on it.

[DawoudSheraz]

@FahadKhalid210 FYI