The hard work of automating rebuilds of the Android SDK has already been done by
the @beuc. It looks like GitHub - ethanc8/SDK-Rebuilds: Free rebuilds of the Android SDK is continuing
with @beuc’s effort.
An overview of the resources needed is here:
https://blog.beuc.net/posts/Android_Rebuilds_updates/
Some of the history of this is available:
The only missing piece is someone to host a trusted build server to run the
builds, and a webserver to host the binaries for people to use. If someone is
ready to take that on, I can help them get setup.