String freeze break exception for user-accounts/parental-controls in GNOME Settings

[Felipe Borges <felipeborges gnome org>]

Hi,

TL;DR: We need to add some keywords to the
gnome-control-center/user-accounts panel desktop file.
https://gitlab.gnome.org/GNOME/gnome-control-center/-/merge_requests/1053

* Rationale:
The GNOME Settings User Accounts panel can [optionally] be built with
parental control capabilities. This adds options to the user interface
allowing for restricting the access to applications to a child user.

While there's a standalone app for configuring parental controls, our
design expects this application to be launched from GNOME Settings.
See https://gitlab.freedesktop.org/pwithnall/malcontent/-/merge_requests/119#note_1052263

This way, we need the User Accounts desktop file to contain keywords
related to parental controls, so the User Accounts panel shows up in
Shell searches. The merge-request for this is at
https://gitlab.gnome.org/GNOME/gnome-control-center/-/merge_requests/1053

Thanks,
Felipe.