Returns a list of offline dictionary metadata available
listOfflineMetadata(cpksver)
  Returns a list of offline dictionary metadata available
Args:
  cpksver: string, The device/version ID from which to request the data. (required)
Returns:
  An object of the form:
    {
    "items": [ # A list of offline dictionary metadata.
      {
        "encrypted_key": "A String",
        "version": "A String",
        "language": "A String",
        "download_url": "A String",
        "size": "A String",
      },
    ],
    "kind": "dictionary#metadata", # Resource type.
  }