I accidentally enrolled my Eclipse game into Google Play App Signing. I somehow thought this was mandatory, now I know it isn't. But Google doesn't allow to step back from this enrollment so I'm stuck with it. All suggestions and tutorials I found on the Internet are related to Android Studio. But I just can't find how to use those Certificates together with Eclipse.
Now I read that once you enroll you can't sign anymore with the original KEY. But for some reasons, this still works in my case. I can export my game with Eclipse and sign it with the original KEY, then upload it to my Google Play Developer Console and it gets accepted. Almost everything works fine. I even can publish the update. BUT, one thing that seems not to work are the Google Play Services. Users can't sign in.
Now the strange thing is that the APK I export from Eclipse is working 100% when I install it manually on a device. Even the leaderboard is working. But once I upload and publish the same APK and I download it from the Play Store, the leaderboard (and Google Play Services) are not working anymore. I guess it is because Google automatically re-signs it with the new Certificates from the Google Play App Signing thing. I think I have now two SHA-1 Certificates. One from my local machine and another one from Google Play App Signing. And then I have as well a Upload Certificate with another SHA-1.
But the only file I can download from the Developer Console is deployment-cert.der and upload-cert.der and I have no clue what to do with it. Again, all instructions I find are for Android Studio and I don't understand them at all. I'm hardly understand the basics of Eclipse.
I read in a lot of other cases that in the end the developer gave up and just re-published his app with a new ID on the Play Store. Unfortunately I can not do that because I don't want to lose over 200 5-star reviews nor my install count. And I surely can't afford it to lose my current players.
So if you have any idea what I should do or know how I should take care of this situation, any help is appreciated.