Add Vulkan job dispatch and flush. (#46008)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/46008
Test Plan: Imported from OSS
Reviewed By: IvanKobzarev
Differential Revision: D24291507
Pulled By: AshkanAliabadi
fbshipit-source-id: a3d02e76708a38e49398bb71e31bb2ad676d01af
