Move from /etc/service to /var/service
Summary:
Same solution than in D2525 / 1c5644246ca2.
Ref T1679
Test Plan: Build image with BuildKit
Reviewers: dereckson
Reviewed By: dereckson
Subscribers: Nasqueron Docker deployment squad
Tags: Docker images
Maniphest Tasks: T1679
Differential Revision: https://devcentral.nasqueron.org/D2607