iOS: Update screen properties more consistently

Instead of updating screen properties (and hence laying out top level
windows) in willAnimateRotationToInterfaceOrientation, we do it in
the more catch-all viewWillLayoutSubviews, which also handles changes
to the orientation while the application is in the background, as well
as changes to the statusbar frame/size, eg. while being in a call.

Change-Id: Ib4a08af2f3a56db426a10ff1ed819867895b5a5a
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

src/plugins/platforms/ios/qiosviewcontroller.mm

@@ -106,13 +106,10 @@
 }
 #endif
 
-- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation duration:(NSTimeInterval)duration
+- (void)viewWillLayoutSubviews
 {
-    Q_UNUSED(duration);
-    Q_UNUSED(interfaceOrientation);
-
     if (!QCoreApplication::instance())
-        return; // FIXME: Store orientation for later (?)
+        return;
 
     m_screen->updateProperties();
 }