The .menu class historically only needs to apply to dropdowns.
the .vectorMenuCheckbox is inconsistent with the other classes on the
menu so we should begin its deprecation.
Bug: T253329
Change-Id: I00b4d2fd795195cd9c8add650a3b3cafdced5465
The classes were recently changed so provided this is merged before
next branch cut no need to worry about cached HTML.
Bug: T249073
Change-Id: Ib20c7a359bda858df89ebb245e682d321dd5acd0
Ed Sanders
jdlrobson