Don't hide keyboard right away

instead keep it around for 200ms. This reduces flicker a lot since the keyboard will not hide when switching through input fields in e.g. contacts or chatty.

this is a 10 minute hack to see if it works and it seems so (most of the time was spent waiting for the rust part to compile). the reduces flicker a lot when switching between fields within an application.

I know we had a bug for this and said it's a toolkit issue but the workaround in squeekboard seems simple enough. if this make sense i can clean it up - the only hacky part is that i removed a hide before a show which should like be more like a schedule redraw anyway i assume?

we still flickr on show/hide but that should indeed be fixed in the compositor.