Add the Cross-Stage FDM menu item to the profile menu for mobile

Fixes an issue where the menu item which directs people to the cross-stage feature discovery moment (FDM) was not showing up for mobile screen sizes. This is because the “Help Menu” where the menu item was added is not shown at mobile screen sizes, but some of the same menu items from the “Help Menu” show up in the “User Profile” menu for mobile screen sizes.

Current mobile menu	Proposed mobile menu

Follow-up to #348494 (closed).