That’s part of the confusion, unfortunately. I am in the beta program. Have been for quite a while, but had forgotten about it.
The build number reported by my app is actually higher than the currently-reported beta app.
The beta announcement thread reports the build as “9.12.0.36793-beta.” The build on my Shield is “9.12.0.36838.” Being a higher build number, I would guess that it is a beta, but lacking the “-beta” suffix (should I see that in the actual app?), I’m not sure that it is. There is no other indication within the app that it is, in fact, a beta build.
So what do I have? By the way, this was all prompted by reports of a new gong sound when the beta app launches, but that’s not happening on mine. So I was lead to wonder whether my build is beta.