how to develop app knowing server will be switched in the near future - need design pattern

parse made the announcement it will soon go away. I need to develop an app which talks to a parse server and save objects there. Eventually I will need to point the Android app to a new server, perhaps a REST server in the near future. I will then need to save objects to this new server. Therefore my question is how shall I proceed as to minimize impact to my Android code when I eventually have to make the switch to the REST server ? I need to minimize code duplication. Can you recommend a design pattern ? I tried to look at ANdroid flavors,but I am hoping there is more than just that.