Apply custom headers in RCTInspectorNetworkHelper (#55610)

Summary:
Pull Request resolved: #55610

Inject custom devsupport headers into inspector resource loading requests. This ensures that inspector network fetches include any registered custom headers.

Changelog:
[Internal] [Changed] -

Reviewed By: cipolleschi

Differential Revision: D93596720

fbshipit-source-id: bda4690a2d9c78729c874977357358a432e46046

Author: cortinico

packages/react-native/React/DevSupport/RCTInspectorNetworkHelper.mm

@@ -6,6 +6,7 @@
  */
 
 #import "RCTInspectorNetworkHelper.h"
+#import <React/RCTDevSupportHttpHeaders.h>
 #import <React/RCTLog.h>
 
 using ListenerBlock = void (^)(RCTInspectorNetworkListener *);
@@ -47,6 +48,7 @@ - (void)loadNetworkResourceWithParams:(const RCTInspectorLoadNetworkResourceRequ
 
   NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:url];
   [urlRequest setHTTPMethod:@"GET"];
+  [[RCTDevSupportHttpHeaders sharedInstance] applyHeadersToRequest:urlRequest];
   NSURLSessionDataTask *dataTask = [self.session dataTaskWithRequest:urlRequest];
   __weak NSURLSessionDataTask *weakDataTask = dataTask;