[PyTorch Mobile]Add light version of RandomSampler (#58201)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58201
Add light version of RandomSampler which can be used torch mobile.
Test Plan: run unit test
Reviewed By: iseeyuan
Differential Revision: D28364467
fbshipit-source-id: 3148129fa56533f5f4b76b63b60e8778eeaf815f
