feat: use centralized tracking image (gitlab.com)

mentioned in commit f861d866

mentioned in merge request to-be-continuous/samples/maven-on-openshift!51 (merged)

mentioned in merge request to-be-continuous/samples/maven-on-gcloud!89 (merged)

mentioned in merge request to-be-continuous/samples/maven-on-kubernetes!101 (merged)

mentioned in merge request to-be-continuous/samples/maven-library!34 (merged)