This is an incomplete styling of the menu.
This should be enough to start an initial design
review and unblock other work on the dropdown.
Out of scope for this patch:
- Pinning (being done in T317900)
- Design (will be done in follow up)
This should cause no visual regressions in Pixel.
Bug: T317899
Change-Id: Id7b47cc16fc8cf93d406687198ba37acf7a9cf24
