[NNAPI] Add fixed-size assertions (#54699)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54699
We'll soon be adding support for flexible-size tensors to the NNAPI
converter, but it won't be added to all ops at once. Create
get_tensor_operand_by_jitval_fixed_size as a wrapper for
get_tensor_operand_by_jitval that verifies that the argument has a fixed
shape. Update all call sites. As flexible size support is added to
each op, the call sites can be converted back and proper size checks
added.
Test Plan: Unit test
Reviewed By: axitkhurana
Differential Revision: D27536791
Pulled By: dreiss
fbshipit-source-id: 6fb1fea814d767b6ff263fd8b88240a51be74777
