Hi Sergio! I was the original author of screenshot-tests-for-android! Back then I promised to open-source a backend service for it, which I never did as part of Facebook. I've since left Facebook, and I have built that out here:

github.com/screenshotbot/screenshotbot-oss

In particular, this is powerful for quick-fix solutions to flaky screenshot tests. You can "mask" out certain parts of the screenshot so that it won't be tested in future runs. Of course, this has some scalability concerns, so I wouldn't use it for everything, but it's a great way to keep the build green while trying to figure out a deterministic fix.