Environment variables in `azdev extension publish` don't work

[Juliehzl]

c.argument('storage_account', help='Name of the storage account to publish to. Environment variable: AZDEV_DEFAULTS_STORAGE_ACCOUNT.', arg_group='Storage', configured_default='storage_account')
c.argument('storage_container', help='Name of the storage container to publish to. Environment variable: AZDEV_DEFAULTS_STORAGE_CONTAINER.', arg_group='Storage', configured_default='storage_container')
c.argument('storage_subscription', help='Subscription ID of the storage account. Environment variable: AZDEV_DEFAULTS_STORAGE_SUBSCRIPTION.', arg_group='Storage', configured_default='storage_subscription')

The environment variables in help message don't work.