Pull artifacts from GAR using OIDC tokens

[Stefan Popov]

As of right now, I was able to find only one way of using a docker image as a container in Bitbucket Pipeline: 

image: name: europe-docker.pkg.dev/csdm-global-assets/pipeline-registry/csdmdev/frontend:20

username: _json_key

password: $PULL_FROM_ARTIFACT_REGISTRY

We don't want to save any service account keys as workspace variables, I am looking for a way of using the OIDC token feature so that the pipeline principal can access the docker image and pull it.