[6/N] Nnapi Backend Delegate: Comprehensive OSS Tests (#61782)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61782
This PR depends on https://github.com/pytorch/pytorch/pull/61787
### Summary:
Added more comprehensive tests for Android NNAPI delegate.
Previously, there was only one basic test for lowering a PReLU module with the NNAPI delegate. Now, more tests are inherited from `test_nnapi.py`, the file for testing NNAPI conversion and execution without the delegate.
**test_backend_nnapi.py**
Test file for Android NNAPI delegate.
- `TestNnapiBackend` class inherits tests from `test_nnapi.py` and overrides the model conversion to use the delegate API.
- Includes an extra test for passing input arguments as Tensors and Tensor Lists.
- Has extra set up for loading the NNAPI delegate library and changing the default dtype from float64 to float32 (dtype is typically float32 by default, but not in delegate backend unit tests)
**test_nnapi.py**
Test file for Android NNAPI without the delegate.
- Some code was refactored to allow override of only the NNAPI conversion call.
- An extra function was added to allow the NNAPI delegate unit test to turn off the model execution step. Once the NNAPI delegate's execution implementation is complete, this may no longer be necessary.
### Test Plan:
I ran `python test/test_jit.py TestNnapiBackend` and `python test/test_nnapi.py` to run both test files.
Test Plan: Imported from OSS
Reviewed By: raziel, iseeyuan
Differential Revision: D29772005
fbshipit-source-id: 5d14067a4f6081835699b87a2ece5bd6bed00c6b
