Confused about structure of android project and MVC pattern

I can't get my head around how to apply the model-view-controller design pattern in an android studio project.

I understand that the view is the .xml layouts and that the activity classes are supposed to be the controllers, but I'm confused about whether general programming logic should be a part of the controller or model.

Can the programming logic related to a particular activity be included within the activity class or should they be separated into two classes? i.e. the activity handling just user input and a second class dealing with the associated programming logic.