To add state_dict and load_state_dict to SequentialLR (#65035)
Summary:
To add state_dict() and load_state_dict() methods to SequentialLR
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65035
Reviewed By: prabhat00155, nateanl
Differential Revision: D30958204
Pulled By: datumbox
fbshipit-source-id: 65114e1b07146526ae2680233f5cd42b2534d67a