The Android app can be built on any OS supported by Android Studio. However, the following automated process is available for Linux x86-64:
If necessary, install Docker using the instructions on its website.
Copy your release key to keystore.jks in this directory. It must contain a key with the
following configuration:
keyAlias "key0"
keyPassword "android"
storePassword "android"
Run build.sh. The APK will be generated in release in this directory.
Between it builds it may be helpful to clear out the docker images with:
docker container prune && docker image prune