change submission to contribution

[jkup]

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

Fix #4521

Test Plan:

Click on Payment History in settings and make sure the text in the footer says contribution instead of submission.

[mrose17]

thanks!