Lists thumbnails of images attached to a step. May return any of the following canonical error
codes: - PERMISSION_DENIED - if the user is not authorized to read from the project, or from any
of the images - INVALID_ARGUMENT - if the request is malformed - NOT_FOUND - if the step does not
exist, or if any of the images do not exist
Create a request for the method "thumbnails.list".
This request holds the parameters needed by the toolresults server. After setting any optional
parameters, call the
AbstractGoogleClientRequest.execute() method to invoke the remote operation.