The Gnome session type boots into the autostart user's Activty Overview.
This overview doesn't allow window activation and fails tst_selftest.
This can't be prevented with gnome-settings or gnome-tweaks.
Add pre-provisioning instruction to select Gnome Classic session type,
which boots into the normal desktop mode.
Fixes: QTBUG-136467
Pick-to: 6.10 6.9
Change-Id: Id189dd948a9a912179e0c86a6cf56f4a2417dfce
Reviewed-by: Tero Heikkinen <tero.heikkinen@qt.io>
Reviewed-by: Jukka Jokiniva <jukka.jokiniva@qt.io>
b3c634b4a5