[ExpressiveDesign] Add a method to provide a content description for the menu button

This is to fix no real context been given to a talk back user when they select the menu preference.

Bug: 441617900
Test: talkback & visual
Flag: EXEMPT BUGFIX
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:68dbc8364571b16d2397fa5ba252cacb7b7819e8
Merged-In: I7220411a96336cbd44de7943f138a1e3632d0185
Change-Id: I7220411a96336cbd44de7943f138a1e3632d0185