fix(ios): cleaning iOS build warnings (#250)

Author: gabrielbiga

packages/firebase-core/platforms/ios/src/TNSFirebaseCore.h

@@ -1,6 +1,6 @@
 #import <Foundation/Foundation.h>
 #import "UIApplicationDelegate+LaunchExtension.h"
-typedef void(^LaunchCallback)();
+typedef void(^LaunchCallback)(void);
 @interface TNSFirebaseCore: NSObject
 +(LaunchCallback) onAppFinishLaunchingCallback;
 +(void) setOnAppFinishLaunchingCallback:(LaunchCallback)callback;

packages/firebase-core/platforms/ios/src/UIApplicationDelegate+LaunchExtension.h

@@ -1,5 +1,5 @@
 #import <UIKit/UIKit.h>
 
 @interface NSObject (TNSUIAppDelegateExt) <UIApplicationDelegate>
-- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(nullable NSDictionary<UIApplicationLaunchOptionsKey, id> *)launchOptions;
+- (BOOL)application:(nullable UIApplication *)application didFinishLaunchingWithOptions:(nullable NSDictionary<UIApplicationLaunchOptionsKey, id> *)launchOptions;
 @end

packages/firebase-core/platforms/ios/src/UIApplicationDelegate+LaunchExtension.m

@@ -3,7 +3,7 @@
 #import <objc/runtime.h>
 
 @implementation NSObject (TNSUIAppDelegateExt)
-- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(nullable NSDictionary<UIApplicationLaunchOptionsKey, id> *)launchOptions {
+- (BOOL)application:(nullable UIApplication *)application didFinishLaunchingWithOptions:(nullable NSDictionary<UIApplicationLaunchOptionsKey, id> *)launchOptions {
     LaunchCallback callback = [TNSFirebaseCore onAppFinishLaunchingCallback];
     if(callback != nil){
         callback();