Automating capture network traffic through browser mob proxy in Appium - appium

Question

I am having trouble getting Browsermob proxy to capture network traffic.
I am using Appium to write tests in android app. I want to use Browser mob proxy to capture and verify network calls. Browser mob proxy is being started at port 19536. I am using a shell script to turn Mac proxy on at port 19536.
Below is the code I am using but I can't see any network requests in the HAR file. Its pretty much empty.
Can someone help? TIA.
Code
//Start Proxy Server
server = new BrowserMobProxyServer();
server.start(19536);
//Turn Mac http Proxy on
Global.runShellCmdWithArg("/usr/local/bin/webproxy.sh", "on");
// get the Selenium proxy object
Proxy seleniumProxy = ClientUtil.createSeleniumProxy(server);
File appDir = new File("/build/outputs/apk/");
File app = new File(appDir, "Demo-debug.apk");
DesiredCapabilities capabilities = new DesiredCapabilities();
capabilities.setCapability("deviceName","Android Emulator");
capabilities.setCapability("platformName", "Android");
capabilities.setCapability("platformVersion", "5.1");
capabilities.setCapability("app", app.getAbsolutePath());
capabilities.setCapability("appPackage", "com.test");
capabilities.setCapability(CapabilityType.PROXY, seleniumProxy);
driver = new AndroidDriver<>(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);
server.enableHarCaptureTypes(CaptureType.REQUEST_CONTENT, CaptureType.REQUEST_BINARY_CONTENT);
server.newHar("newHar");
testApp = new DemoAppPage(driver);
wait = new WebDriverWait(driver, 30);
testApp.clickGetStarted();
testApp.clickButton();
// Get the HAR data
Har har = server.getHar();
File harFile = new File("test.har");
har.writeTo(harFile);