fix: Keyboard layout shortcuts activate wrong language

Fixes spare layout's shortcuts activating wrong layout after the first
use, see the bug for the details.

When we switch to a spare layout (by the shortcuts or via applet's
menu), rearrangement of layouts happen - the spare one becomes the last
in the main loop, preempting the previous one on it's place.

Layouts-specific shortcut actions activate the layout by index which is
hold in the action's data. Thus, the indexes should be adjusted
accordingly.

BUG: 444569


(cherry picked from commit 7525b4a6)