build: add server-side rendering check for kml layer (#20147)

Adds the new KML layer component to the server-side rendering checks.

Author: crisbeto

src/universal-app/kitchen-sink/kitchen-sink.html

@@ -416,4 +416,6 @@ <h2>Google Map</h2>
       west: 10,
       south: -5
     }"></map-ground-overlay>
+    <map-kml-layer
+      url="https://developers.google.com/maps/documentation/javascript/examples/kml/westcampus.kml"></map-kml-layer>
 </google-map>