[PBIOS-589] Fix Typeahead dropdown scroll on key pressed (#476)

**What does this PR do?** A clear and concise description with your
runway ticket url.
I want to use the down arrow keys to navigate through typeahead results,
So that the dropdown display scrolls correctly as I move through the
list of results.

**Screenshots:** Screenshots to visualize your addition/change


**How to test?** Steps to confirm the desired behavior:
1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See addition/change

### Checklist
- [ ] **LABELS** - Add a label: `breaking`, `bug`, `improvement`,
`documentation`, or `enhancement`. See
[Labels](https://github.com/powerhome/playbook-apple/labels) for
descriptions.
- [ ] **RELEASES** - Add the appropriate label: `Ready for Testing` /
`Ready for Release`
- [ ] **TESTING** - Have you tested your story?

Author: isismsilva