logdevice for generic feature type (#16191)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16191
logdevice related modifications for generic feature type
we directly convert the generic feature structures to json strings, which corresponds to the column input in offline and dper
Reviewed By: itomatik
Differential Revision: D13551909
fbshipit-source-id: 807830c50bee569de202530bc3700374757793a2
