Facebook app automation using appium; after clicking on login in app; fb app closes itself

Support
1

public class connect1fb1 {

public static AndroidDriver<AndroidElement> capabilities1() throws MalformedURLException {
 DesiredCapabilities cap1 = new DesiredCapabilities();
   cap1.setCapability(MobileCapabilityType.DEVICE_NAME,"test_emulator_fb");
  	   cap1.setCapability("appPackage","com.facebook.katana");
cap1.setCapability("appActivity", "com.facebook.katana.platform.FacebookAuthenticationActivity");
cap1.setCapability("appium-version", "1.7.1");
	cap1.setCapability("platformnName","Android");
	cap1.setCapability("platformVersion","7.0");
	cap1.setCapability("newCommandTimeout","12000");
	AndroidDriver<AndroidElement> driver1= new AndroidDriver<>(new URL("http://localhost:4723/wd/hub"),cap1);
return driver1;
	
}

}