Move Android Nnapi srcs from aten_native_cpu to aten_cpu (#62919)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62919
Move Android NNAPI srcs (nnapi_bind.cpp, nnapi_wrapper.cpp, nnapi_model_loader.cpp) from aten_native_cpu to aten_cpu, so that later the NNAPI delegate's execution library can depend on it.
aten_native_cpu is built selectively per app, but the srcs have no selective components and are required for the NNAPI delegate library in D30259033.
See Buck Dependencies: https://docs.google.com/document/d/17RuWkqWKCO6sc5fKzIDkGeNhhvMk7BvJOqeSnGsHZ8o/edit?usp=sharing
ghstack-source-id: 135981062
Test Plan: `buck build --show-output arstudioplayer_arm64_debug` and internal tests
Reviewed By: iseeyuan
Differential Revision: D30164867
fbshipit-source-id: 0beff481ff250e75664ce8393beabbeb9db66770
