it seems like there is no way to specify source_version / branch name in codebuild module. in aws cli we can specify branch or tags etc

"sourceVersion": "source-version",
  "secondarySourceVersions": {
    "sourceIdentifier": "secondary-source-identifier",
    "sourceVersion": "secondary-source-version"
  }, 
<https://docs.aws.amazon.com/codebuild/latest/userguide/create-project.html#create-project-cli>