Update container registry to use v2.7.4-gitlab

v2.7.3-gitlab updates the storage driver to use the latest Google SDK: gitlab-org/container-registry!2 (merged)

v2.7.4-gitlab fixes an issues with v2.7.3-gitlab with non-default Google credentials: gitlab-org/container-registry!7 (merged)

This registry upgrade hopefully will fix 0-byte upload issues: https://github.com/googleapis/google-cloud-go/issues/746