Perform actions outside mobile web app in Android

I am writing test cases for my web application and start the appium in ruby. these are my capabilities

platformName = “Android”
deviceName = “”
platformVersion = “4.4.2”
browserName = “Chrome”
custom_url = “http://localhost:4723/wd/hub

My application interact with Native camera app and i want to perform actions on it. Is it possible simulate these action through UIautomator in appium. Any help is appreciated. Thanks.