docs: Added call to build to code snippet

Bug: 28986465
Change-Id: Idca4b02859fdd1ce7f5b633c2a2a183ea3034f41
diff --git a/docs/html/preview/features/notification-updates.jd b/docs/html/preview/features/notification-updates.jd
index af449cb..fd65e12 100644
--- a/docs/html/preview/features/notification-updates.jd
+++ b/docs/html/preview/features/notification-updates.jd
@@ -395,5 +395,6 @@
                  .addMessage("Hi", timestamp1, null) // Pass in null for user.
                  .addMessage("What's up?", timestamp2, "Coworker")
                  .addMessage("Not much", timestamp3, null)
-                 .addMessage("How about lunch?", timestamp4, "Coworker"));
+                 .addMessage("How about lunch?", timestamp4, "Coworker"))
+             .build();
 </pre>