Follow framework API change in TaskStackBuilder

Change-Id: I8d83c2a680b2004fded46630166fc1f9b09a5038
diff --git a/samples/AppNavigation/src/com/example/android/appnavigation/app/NotificationsActivity.java b/samples/AppNavigation/src/com/example/android/appnavigation/app/NotificationsActivity.java
index bf338be..cfb3b42 100644
--- a/samples/AppNavigation/src/com/example/android/appnavigation/app/NotificationsActivity.java
+++ b/samples/AppNavigation/src/com/example/android/appnavigation/app/NotificationsActivity.java
@@ -41,7 +41,7 @@
                 .setContentTitle("Direct Notification")
                 .setContentText("This will open the content viewer")
                 .setAutoCancel(true)
-                .setContentIntent(TaskStackBuilder.from(this)
+                .setContentIntent(TaskStackBuilder.create(this)
                         .addParentStack(ContentViewActivity.class)
                         .addNextIntent(new Intent(this, ContentViewActivity.class)
                                 .putExtra(ContentViewActivity.EXTRA_TEXT, "From Notification"))