[FSDP][BE] remove get_full_params() from test code (#73242)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/73242
Can use summon_full_params instead.
ghstack-source-id: 149800364
Test Plan: CI
Reviewed By: zhaojuanmao
Differential Revision: D34399789
fbshipit-source-id: 8552cdf3ed003aba1316f554f4ec457fdada5dbe
(cherry picked from commit a397e2dfd3750afe1d21cdee3aa4c2d525ed837e)
