Missing classpath elements on component-server for CE

(Following jib migration in TCOMP-2367) jib gives different classpath management as layerspector for generating the component-server docker image.
Some classpath elements are missing according the platform from where is run the component-server:
On remote-engine the custom extensions artifacts are located in the volume connectors mounted into /opt/talend/component-kit/custom/.
On CE, the mount volume is /opt/talend/custom which is not in the scope of the classpath generated automatically by jib.