keyboard: Do the initial redraw in _init

It doesn't seem like there's anything preventing us from doing this.

https://bugzilla.gnome.org/show_bug.cgi?id=692678

js/ui/main.js

@@ -173,7 +173,7 @@ function start() {
     componentManager = new Components.ComponentManager();
 
     layoutManager.init();
-    keyboard.init();
+    layoutManager.prepareStartupAnimation();
     overview.init();
 
     global.screen.override_workspace_layout(Meta.ScreenCorner.TOPLEFT,