In portrait orientation, we set the height to the preferred height
for the monitor width (or, if smaller, a third o the screen height).
However as the forWidth currently doesn't make a difference, the height
is effectively controlled by the natural height of the keys - which is
rather small.
Address this by making AspectContainer request an appropriate preferred
size based on the fixed ratio.
https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2349
261d36ba72