Update RNGoogleMobileAdsNativeModule.mm

Author: malandr2

ios/RNGoogleMobileAds/RNGoogleMobileAdsNativeModule.mm

@@ -215,7 +215,7 @@ - (void)adLoader:(nonnull GADAdLoader *)adLoader
   _nativeAd.delegate = self;
   _nativeAd.paidEventHandler = ^(GADAdValue *_Nonnull adValue) {
     NSDictionary *revenueData = @{
-      @"value" : [adValue.value doubleValue],
+      @"value" : @([adValue.value doubleValue]),
       @"precision" : @(adValue.precision),
       @"currency" : adValue.currencyCode ?: @""
     };