UnityWebRequest instead of UniWeb

            // Construct JSON request body.
            JSONObject requestJSON = new JSONObject();
            JSONObject requestConfig = new JSONObject();
            requestConfig.AddField(Constants.GoogleRequestJSONConfigEncodingFieldKey, "FLAC");
            requestConfig.AddField(Constants.GoogleRequestJSONConfigSampleRateFieldKey, "16000");
            requestConfig.AddField(Constants.GoogleRequestJSONConfigLanguageCodeFieldKey, "ru-RU");
            JSONObject requestAudio = new JSONObject();
            requestAudio.AddField(Constants.GoogleRequestJSONAudioContentFieldKey, Convert.ToBase64String(File.ReadAllBytes(flacAudioFilePath)));
            requestJSON.AddField(Constants.GoogleRequestJSONConfigFieldKey, requestConfig);
            requestJSON.AddField(Constants.GoogleRequestJSONAudioFieldKey, requestAudio);

            string url = Constants.GoogleNonStreamingSpeechToTextURL +
                         "?" + Constants.GoogleAPIKeyParameterName + "=" + m_APIKey;

            UnityWebRequest www = new UnityWebRequest(url, UnityWebRequest.kHttpVerbPOST);

            byte[] bytes = Encoding.UTF8.GetBytes(requestJSON.ToString());

            UploadHandlerRaw uH = new UploadHandlerRaw(bytes);
            uH.contentType = "application/json";
            www.uploadHandler = uH;

            www.downloadHandler = new DownloadHandlerBuffer();

            www.SetRequestHeader("Content-Type", "application/json");

            SmartLogger.Log(DebugFlags.GoogleNonStreamingSpeechToText, "sent request");

            yield return www.Send();

            while (!www.isDone)
            {
                yield return null;
            }

            if (www.isError)
            {
                SmartLogger.Log(DebugFlags.GoogleNonStreamingSpeechToText, www.error);
            }
            else
            {
                SmartLogger.Log(DebugFlags.GoogleNonStreamingSpeechToText, "Form upload complete!");
            }

            // Grab the response JSON once the request is done and parse it.
            var responseJSON = new JSONObject(www.downloadHandler.text, int.MaxValue);