Add debug logs to print custom signals during updates and fetches.

Author: tusharkhandelwal8

FirebaseRemoteConfig/Sources/FIRRemoteConfig.m

@@ -337,6 +337,9 @@ - (void)setCustomSignals:(nullable NSDictionary<NSString *, NSObject *> *)custom
     if (![newCustomSignals isEqualToDictionary:self->_settings.customSignals]) {
       self->_settings.customSignals = newCustomSignals;
     }
+    // Log the final updated custom signals.
+    FIRLogDebug(kFIRLoggerRemoteConfig,  @"I-RCN000078",@"Updated custom signals: %@", newCustomSignals);
+
     if (completionHandler) {
       dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
         completionHandler(nil);

FirebaseRemoteConfig/Sources/RCNConfigSettings.m

@@ -458,6 +458,9 @@ - (NSString *)nextRequestWithUserProperties:(NSDictionary *)userProperties {
                                                        [[NSString alloc]
                                                            initWithData:jsonData
                                                                encoding:NSUTF8StringEncoding]]];
+      // Log the custom signals during fetch.
+      FIRLogDebug(kFIRLoggerRemoteConfig,  @"I-RCN000078",@"Fetching with custom signals: %@", _customSignals);
+      
     }
   }
   ret = [ret stringByAppendingString:@"}"];