It should be possible somehow, but i do not use androidenv.
I found that we used to have androidenv.buildGradleApp init androidenv.buildGradleApp by matthewbauer · Pull Request #41855 · NixOS/nixpkgs · GitHub
but it was removed in Mobile updates by svanderburg · Pull Request #50596 · NixOS/nixpkgs · GitHub which has
Readd androidenv.buildGradleApp in Still to do:
perhaps we could readd it using https://github.com/reflex-frp/reflex-platform/blob/7e35474f01e70500ea5c0d903a4e7df92068aee6/android/build-gradle-app.nix (which was where the original implementation was from) as a base