Replace GCLOUD_PROJECT with GOOGLE_CLOUD_PROJECT. [(#4022)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/4022)
Replace GCLOUD_PROJECT with GOOGLE_CLOUD_PROJECT. [(#4022)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/4022)


googleapis/python-containeranalysis,googleapis/python-containeranalysis