Update base for Update on "[ET-VK] Implement `native_group_norm"

## Changes

* Add implementation for the group norm operator.

The operator is implemented via a 2 stage implementation. First, a reduction operator is executed to calculate the mean and standard deviation of each channel group. Then, the normalization is applied in an elementwise fashion.

Differential Revision: [D77038778](https://our.internmc.facebook.com/intern/diff/D77038778/)

[ghstack-poisoned]

Author: SS-JIA