Vulkan command buffer and pool. (#42930)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/42930
Test Plan: Imported from OSS
Reviewed By: IvanKobzarev
Differential Revision: D23252333
Pulled By: AshkanAliabadi
fbshipit-source-id: 738385e0058edf3d3b34173e1b1011356adb7b3c
