By default gradle spawns a daemon which keeps on running in the
background long after the package has been built and taking up
precious ram. Avoid this.
Update the android sdk build tools from 27.0.3 to 28.0.1, bringing
in d8 which is replacing dx.
This needs an update of the Docker image, so run scripts/update-docker.sh
to update it.
Wetitpig
Leonid Plyushch
Fredrik Fornwall