gnome-base/gnome-control-center: bump to 3.28.2

gnome-base/gnome-control-center: bump to 3.28.2

colord is no longer partially optional, because it is needed by
display panel for night light anyways, so didn't bother with
making the color profile management panel optional either. It
does mean an unconditional colord-gtk and gnome-color-manager
dep, but so be it - if colord and core code pulled in via
gnome-settings-daemon[colord] already, might as well make full
use of it always.
Instead grilo is now separately optional from gnome-online-accounts,
as this is about background images from flickr, which needs separate
extra runtime deps too.

Package-Manager: Portage-2.3.52, Repoman-2.3.12
Signed-off-by: Mart Raudsepp <leio@gentoo.org>