Hi Matthews;
Currently, PB2019 R2 and it's embedded PS2020 are only "beta" releases. They are not fully outfitted to deploy Apps in a production manner. This beta is only for testing.
For your Android mobile apps, please install the AWS runtime via using the "over the air" install procedure driven by the AEM login screen. Once AWS is installed on your Android device, use the App configuration feature within AWS to setup your PB Mobile App. Then, run & test only your mobile solution from there for the time being.
Once both PB2019R2 & PS2020 go GA, then you can then commence formal AWS and/or App packaging via the "formal" publishing route.
Regards... Chris