lomiri greeter: in usageMode 'desktop' the login prompt is moved to far up if the OSK pops in
How to reproduce this issue:
* Install Debian 13 minimal on physical hardware (e.g. a notebook) or a VM, and run `apt install lomiri` afterwards. Reboot.
* This issue happens in Lomiri Greeter, so don't log into the Lomiri session.
* Click on the keyboard icon in the username / password prompt of the greeter
* Observe.
* As a 2nd step: Then switch to a TTY and add this content:
```
[com.lomiri.Shell]
usage-mode='Staged'
```
to a new file named ``/usr/share/glib2.0/schemas/99_lomiri.override``
* Run ``glib-compile-schemas /usr/share/glib2.0/schemas`` to activate the new override.
* Restart LightDM (``invoke-rc.d lightdm restart``)
What you will observe:
* The OSK comes up and the username / password field is moved way up to a place near the top border of the screen (TOO FAR)
* After you have enforced the window manager mode to "Staged", the username/password field behaves well and is only moved a little bit up
What should happen:
In 'windowed' or Desktop mode, the OSK should move the username/password field up slightly, so that the user experience matches with the behaviour in staged mode
issue