String freeze request for gnome-shell

[Florian Müllner <fmuellner gnome org>]

Hi y'all!

When fixing keyboard navigation on the new lock screen(*), I noticed
that we also broke screen readers when turning text buttons into image
buttons.

The fix is to add a (translatable) accessible name:
"Log in as another user"

This is the same string that was previously used for the text button,
so the impact on translations should be small: In the best case, the
translation still exists, in the worse case it has to be resurrected
from before 3.35.91.

Regards,
Florian

(*) https://gitlab.gnome.org/GNOME/gnome-shell/issues/2210
   https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1030