Add interceptors and request headers

Add log interceptor

        OkHttpClient.Builder httpClientBuilder = new OkHttpClient.Builder();
        //Add log interceptor in DEBUG mode
        if(BuildConfig.DEBUG){
            HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
            interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
            httpClientBuilder.addInterceptor(interceptor);
        }

Set request headers

        //Add a set header interceptor
        //header User-Agent device system/app version number (system version number of the device; device model)
        httpClientBuilder.addInterceptor(new Interceptor() {
            @Override
            public Response intercept(Chain chain) throws IOException {
                Request mRequest = chain.request().newBuilder()
                        .header("User-Agent","android/" +
                                App.VERSIONNAME + "(" +
                                DeviceUtils.getSDKVersion() + ";" +
                                DeviceUtils.getModel() + ")")
                        .build();
                return chain.proceed(mRequest);
            }
        });

mRetrofit = new Retrofit.Builder()
                .client(httpClientBuilder.build())