Fix the crash from okhttp interceptor (#168)

Summary:
Add a null check before creating a new response
Fixes #166
Pull Request resolved: https://github.com/facebook/Sonar/pull/168

Reviewed By: jknoxville

Differential Revision: D8915871

Pulled By: passy

fbshipit-source-id: aa93273f6fe90a8160133331e0844f67ff7e620a

android/src/main/java/com/facebook/sonar/plugins/network/SonarOkhttpInterceptor.java

@@ -1,4 +1,10 @@
-// Copyright 2004-present Facebook. All Rights Reserved.
+/*
+ *  Copyright (c) 2004-present, Facebook, Inc.
+ *
+ *  This source code is licensed under the MIT license found in the LICENSE
+ *  file in the root directory of this source tree.
+ *
+ */
 package com.facebook.sonar.plugins.network;
 
 import android.util.Log;
@@ -39,10 +45,14 @@ public class SonarOkhttpInterceptor implements Interceptor {
     ResponseInfo responseInfo = convertResponse(response, body, randInt);
     plugin.reportResponse(responseInfo);
     // Creating new response as can't used response.body() more than once
+    if (responseInfo.body != null) {
       return response
           .newBuilder()
           .body(ResponseBody.create(body.contentType(), responseInfo.body))
           .build();
+    } else {
+      return response;
+    }
   }
 
   private static byte[] bodyToByteArray(final Request request) {