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

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

Differential Revision: [D68400677](https://our.internmc.facebook.com/intern/diff/D68400677/)

[ghstack-poisoned]

Author: trivedivivek