Fix RNTester networking conversion to TurboModule (#27218)

Summary:
Now that the networking module is a TurboModule request handlers need to be passed at module creation. The code was missing for RNTester.

## Changelog

[Internal] [Fixed] - Fix RNTester networking conversion to TurboModule
Pull Request resolved: https://github.com/facebook/react-native/pull/27218

Test Plan: Tested that RNTester XMLHttpRequest example now works on iOS

Differential Revision: D18506038

Pulled By: RSNara

fbshipit-source-id: cd88319e386c7b7b6e11cfb920f2ceb761a4136a

RNTester/RNTester/AppDelegate.mm

@@ -16,6 +16,10 @@
 #import <React/RCTImageLoader.h>
 #import <React/RCTLocalAssetImageLoader.h>
 #import <React/RCTGIFImageDecoder.h>
+#import <React/RCTNetworking.h>
+#import <React/RCTHTTPRequestHandler.h>
+#import <React/RCTDataRequestHandler.h>
+#import <React/RCTFileRequestHandler.h>
 #import <React/RCTRootView.h>
 
 #import <cxxreact/JSExecutor.h>
@@ -151,6 +155,14 @@
     } decodersProvider:^NSArray<id<RCTImageDataDecoder>> *{
       return @[[RCTGIFImageDecoder new]];
     }];
+  } else if (moduleClass == RCTNetworking.class) {
+    return [[moduleClass alloc] initWithHandlersProvider:^NSArray<id<RCTURLRequestHandler>> *{
+      return @[
+        [RCTHTTPRequestHandler new],
+        [RCTDataRequestHandler new],
+        [RCTFileRequestHandler new],
+      ];
+    }];
   }
   // No custom initializer here.
   return [moduleClass new];