Update Cloud Build deployment local-exec step

[zefdelgadillo]

The Cloud Build deployment step, which creates two container images and saves them to artifact registry is failing because of a deprecated gcloud flag cloud_run.tf#L85:

ERROR: (gcloud.builds.submit) unrecognized
│ arguments: --git-source-dir=. (did you mean '--gcs-source-staging-dir'?)

A few options to fix this include:

1. (Quick fix) Remove --git-source-dir=. from the script, then cloud build simply use the local directory for the build.
2. Decouple Cloud Build from Terraform as proposed in #104; we could further consolidate by including Cloud Run deployments into the cloudbuild.yaml file
3. Replace local-exec with a Cloud Build trigger terraform resource