Add magic wait time to aaa_setup

tests/applications/gnome-initial-setup/aaa_setup.pm

@@ -16,7 +16,9 @@ sub run {
     # Remove the user clear the system and force the gnome-initial-setup
     # to start on new boot.
     assert_script_run("loginctl kill-user $username");
-    # that might switch us back to GDM, switch away if so
+    # do nothing for 10 seconds to give the previous command finish correctly
+    sleep(10);
+    # closing the user might switch us back to GDM, switch away if so
     $self->root_console(tty => 3) if (check_screen 'graphical_login', timeout => 30);
     assert_script_run("userdel -r $username");