Fix warning.

Author: dmandar

Example/DynamicLinks/FDLBuilderTestAppObjC/AppDelegate.m

@@ -60,7 +60,7 @@ - (BOOL)application:(UIApplication *)application
 
 - (BOOL)application:(UIApplication *)application
     continueUserActivity:(NSUserActivity *)userActivity
-      restorationHandler:(void (^)(NSArray *))restorationHandler {
+      restorationHandler:(void (^)(NSArray<id<UIUserActivityRestoring>> * _Nullable))restorationHandler {
   BOOL handled = [[FIRDynamicLinks dynamicLinks]
       handleUniversalLink:userActivity.webpageURL
                completion:^(FIRDynamicLink *_Nullable dynamicLink, NSError *_Nullable error) {