BrowserMenu - `endOfMenuAlwaysVisible = true` has no effect

[Mugurell]

This is a regression from #9879 which still uses this endOfMenuAlwaysVisible property but sets it at a later time and seemingly it is too late for it to have an effect.

This was the true cause of some UI tests failing here - mozilla-mobile/fenix#18619 where @sv-ohorvath saw that the menu looks to have different options because it is not scrolled to the bottom anymore.

┆Issue is synchronized with this Jira Task