WMPolicy: set initial size for new window with certain state
Set size of windows in certain state immediately so that apps can start rendering correctly right away. We have to do this because MirAL (apparently) don't have an idea on various UIs drawn using Qt.
In particular, this makes sure Waydroid has the correct initial size, as it cannot be resized afterwards (because of how Android works, I guess).
Bug: ubports/development/core/packaging/waydroid#15 (closed)