window-list: Fix OSK

The reveal animation moved from Main.layoutManager.keyboardBox to
the keyboard itself, so instead of applying an additional translation
for the bottom panel, we override the translation that would reveal
the keyboard (and thus prevent it from showing altogether).

Fix this by moving our translation to the keyboardBox instead.

(cherry picked from commit 02e5029e)

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/merge_requests/202>