Is adding a donation link to an Android app a violation of Developer Agreement?

I am looking into the proper way of adding a donation button to my Android app without violating any developer agreement or terms of service. I looked into the Google in-app billing solution, as I was under the impression that it is allowed, since I see many apps that do this very thing.

However, after closer inspection, it appears that I cannot use Google's in-app billing for donations, as clearly stated on Google's help pages (can't post link as I am a new user).

I also read elsewhere on Stackoverflow that I should be able to add a link to a web page on my website, for example, that directs users to donate if they so desire. Is adding such a link inside my android app a violation of the developer distribution agreement? May be because I am using a third party solution for payments?