We changed to only show access time for sorting in the sort menu
in 3.16 to avoid having both sorting options always present.
But for folders like Downloads, the most useful sorting criteria is
actually modified time, since it orders the files in downloading order.
Actually modified time is more useful than access time is all cases
except in "Recent", which what we actually want is the most recent
accessed or modified file.

For that, show only Modified Time sorting menu item in all places
except in "Recent", where we will show only Access Time.

https://bugzilla.gnome.org/show_bug.cgi?id=748185