Dataset File Listing: Sort Order for Newest/Oldest is backwards

[shlake]

What steps does it take to reproduce the issue?
On a dataset file listing, click "Sort -> Newest"
The resulting order is oldest first.

On a dataset file listing, click "Sort -> Oldest"
the resulting order is newest first.

• When does this issue occur?
  On the Dataset file listing section

• To whom does it occur (all users, curators, superusers)?
  All Users

• What did you expect to happen?
  Newest should be sorted "descending" (desc), but Oldest is sorted that way

Which version of Dataverse are you using?
V6.2

Happens on my local V6.2 dataverse instance as well as on Harvard's (V6.2):
Example, This dataset: https://doi.org/10.7910/DVN/KFVIIH

This is the URL that is displayed when "Oldest" sort is selected - notice "fileSortOrder=desc"

https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/KFVIIH&version=&q=&fileTypeGroupFacet=&fileAccess=&fileSortField=date&fileSortOrder=desc&tagPresort=false