chore(python): upgrade gcp-releasetool in .kokoro [autoapprove]#407

parthea merged 2 commits intomaingoogleapis/python-videointelligence:mainfrom

owl-bot-update-lock-8555f0e37e6261408f792bfd6635102d2da5ad73f8f09bcb24f25e6afb5fac97googleapis/python-videointelligence:owl-bot-update-lock-8555f0e37e6261408f792bfd6635102d2da5ad73f8f09bcb24f25e6afb5fac97Copy head branch name to clipboard