Update table's field names in measurements JSON file

[mthmsn]

The JSON file fields names listed in the table here are formatted incorrectly:
https://github.com/mlcommons/policies/blob/master/submission_rules.adoc#system_desc_id_implementation_id_scenario-json-metadata

A submitter must have the field names formatted correctly for the submission checker to not throw an error. Please update the table to use the correct field names, which are:

starting_weights_filename
weight_transformations
weight_data_types
input_data_types
retraining