Update on "[ET-VK] Applying bias after sum calculation in conv2d pw shader to improve performance."

This diff improves the performance of the conv2d pw shader by changing the order of operations to apply bias after the sum calculation.

Differential Revision: [D75450662](https://our.internmc.facebook.com/intern/diff/D75450662/)

[ghstack-poisoned]

Author: trivedivivek