An Android App Bundle (AAB) is the signed Android build artifact produced for release and passed from a GitHub Actions build job to a later deployment job. section 12.2.2
Publishing a signed bundle
Run dotnet publish for the MAUI project with -f:net7.0-android, -c:Release, and Android signing properties, then upload the matching *Signed.aab path as a workflow artifact.
Figure 12.8 The first step in this job checks out the code from the repo. The next will retrieve the Android signing keystore from GitHub Actions secrets and convert it from a base64 string. The next two steps set up dependencies (.NET and the .NET MAUI workloads). After that, the next step creates a signed build, and the final step uploads the signed build to GitHub, ready for the deploy job to pick it up later.
Follow the workflow from checkout and secret-based keystore recovery through dependency setup, signed publishing, and artifact upload. section 12.2.2
