What are you trying to do?

reduce the number of layers in the docker image;
reduce the size of the layers in the docker image;
update gradle version ;
update golang version

How should we solve this?

Changes proposed in PR tailscale/tailscale-android#636

Step-by-step refactor in https://github.com/smikes/tailscale-android/tree/smikes/simplify-docker-expanded

What is the impact of not solving this?

Android build image currently embeds an older golang installation, which means that
builds using this image must immediately download golang 1.24.1 ; this makes builds slower

Layers that are larger than needed make it slower to download and use the image

Anything else?

No response