Update on "[ET-VK] Fix OSS build by replace starts_with usage"

`starts_with` is a C++20 feature but OSS is on C++17.

https://en.cppreference.com/w/cpp/string/basic_string/starts_with

Differential Revision: [D64076249](https://our.internmc.facebook.com/intern/diff/D64076249/)

[ghstack-poisoned]

Author: jorgep31415