[iOS][GPU] Consolidate array and non-array kernel for upsampling_nearest2d (#63061)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/63061
Cleanup the redundant shader code for the upsampling nearest kernel.
ghstack-source-id: 135524349
Test Plan:
- `buck test pp-macos`
- Op tests in PyTorchPlayground app
Reviewed By: husthyc
Differential Revision: D30236905
fbshipit-source-id: e1e001b446452b077e6db719b0519c9070f3300b
