The APKs are ready. I have built, signed and uploaded the APKs:
Krita-x86-signed.apk
Krita-arm64-signed.apk
Krita-arm32-signed.apk
I am sorry, it took me quite a while to upload this. Unfortunately, before giving out APKs I wanted to make a patch to hide that hideously big Menu Bar forever. I tried to wrestle Qt to make it happen and it did kind of happen, but in a very ugly and non-deterministic way. So, I guess it will take some more time before it is ready 
Thank you for testing!
PS: I noticed, when you start Krita for the first time (after freshly installing the app). It takes time to load resources (arm64 about 30 seconds, arm32 about a minute). I am assuming this has something to do with the latest resource rewrite being done on master.