How can we automate built-in apps with appium?

Hello, the very first activity of contacts is “com.android.dialer.DialtactsActivity”.
So, I replaced the line

cap.setCapability(AndroidMobileCapabilityType.APP_ACTIVITY, “com.samsung.android.contacts.activities.PeopleActivity”);

to

cap.setCapability(AndroidMobileCapabilityType.APP_ACTIVITY, “com.android.dialer.DialtactsActivity”);

and it worked.

Thanks