Update on "[ET-VK] Modify conv 2d pw op shader and dispatch settings to linearly dispatch work accounting for linearity texture to improve performance."

This diff modifies the convolution 2D pointwise op shader and dispatch settings to linearly dispatch work accounting for linearity texture to improve performance.

Differential Revision: [D67683411](https://our.internmc.facebook.com/intern/diff/D67683411/)

[ghstack-poisoned]

Author: trivedivivek