fix(controller): Use correct entrypoint for run

Running commands in an image build using git push requires to use ‘/runner/init’ as entrypoint, otherwise environment variables inject by buildpacks are missing.

Fixes #1801, fixes #1568
I'm not sure that I understand you right. Entrypoint is generally optional an only required in the special run template. Do you want to set an empty entrypoint or `/bin/bash` as default?