Update on "[ET-VK][ez] Handle zero-element tensors when building Vulkan graph"

## Changes

As title.

## Motivation

Some models may have parameter tensors which are zero-shape (i.e. no elements). In this case, trying to serialize the tensor data will result in a null pointer exception.

Differential Revision: [D77281492](https://our.internmc.facebook.com/intern/diff/D77281492/)

cc manuelcandales cbilgin

[ghstack-poisoned]

Author: SS-JIA