layout: Inform client to resize for fullscreen roles

layout: Inform client to resize for fullscreen roles

In a previous patch we optimized sending the dimensions from the start,
but in some situations the client might set up the surface roles
*after* that happens, which might lead to issue as we are explicitly
terminating the connection if the client wasn't correctly resized by
that time.

This corrects that such that even if we perform a late set-up for the
fullscreen role, we can still tell the client to resize, and later on to
display the surface.

Bug-AGL: SPEC-4339
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: I491c60c9881e99bc3201216a842782417286f0d9