If he was a made member and if Riina was his Godfather than that was the greatest success of the Beast
If somebody made him (which I doubt), it was surely not Riina. Andreotti was close with the "traditionalists" of the Cosa Nostra: Stefano Bontate, Gaetano Badalamenti, Vincenzo and Filippo Rimi. But with Riina he wasn't on very good terms. He might have negotiated with him or even covered up for him out of fear, but Riina doesn't have any diplomatic skills. He is just another Casso, even though more powerful.