Update on "[ET-VK] Using push constants for conv2d dw."

This diff is related to the use of push constants for convolutional dw (depthwise) in Executorch's Vulkan backend. This optimization improves memory usage.

Differential Revision: [D68493849](https://our.internmc.facebook.com/intern/diff/D68493849/)

[ghstack-poisoned]

Author: trivedivivek