[T124977342] Clean up duplicated code in vulkan_api_test (#81834)
Test Plan: https://www.internalfb.com/intern/skycastle/run/99079191809162516/actions?defaultSelectedActionId=99079191947773855
Differential Revision: D38017886
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81834
Approved by: https://github.com/kirklandsign
