fix(router): don't use spread operator to workaround an issue in closure compiler (#22884)

Closure compiler could not handle the spread operator in this one place. Working around it by removing the use of spread operator.

PR Close #22884

packages/router/src/utils/collection.ts

@@ -84,7 +84,8 @@ export function waitForMap<A, B>(
     }
   });
 
-  return of (...waitHead, ...waitTail).pipe(concatAll(), lastValue(), map(() => res));
+  // Closure compiler has problem with using spread operator here. So just using Array.concat.
+  return of .apply(null, waitHead.concat(waitTail)).pipe(concatAll(), lastValue(), map(() => res));
 }
 
 /**