Fix dropdown.js path

[luixxiul]

This is a follow-up to #8443

Auditors:

Test Plan: npm run watch should work

• 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).

[bsclifton]

++