Immutable. Full name of the Cloud Filestore Backup resource that this Share is restored from, in the format of projects/{project_id}/locations/{location_id}/backups/{backup_id}. Empty, if the Share is created from scratch and not restored from a backup.
Required. The ID to use for the share. The ID must be unique within the specified instance. This value must start with a lowercase letter followed by up to 62 lowercase letters, numbers, or hyphens, and cannot end with a hyphen.