Delete: Deletes the specified attachment for the given beacon. Each attachment has a unique attachment name (`attachmentName`) which is returned when you fetch the attachment data via this API. You specify this with the delete request to control which attachment is removed. This operation cannot be undone. Authenticate using an [OAuth access token](https://developers.google.com/identity/protocols/OAuth2) from a signed-in user with **Is owner** or **Can edit** permissions in the Google Developers Console project.