Make NNAPI linear converter accept flex inputs (#61022)
Summary:
As title
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61022
Test Plan: pytest test/test_nnapi.py::TestNNAPI::test_linear
Reviewed By: anshuljain1
Differential Revision: D29480749
fbshipit-source-id: 35975861740298c9e16f866c939e7ee3c2151710
