[image-picker] Avoid dependency on uuid

[LinusU]

Why

Older versions of uuid is deprecated. And, as far as I could tell, there was no need for it in this module.

uuid@3.4.0: Please upgrade to version 7 or higher. Older versions may use Math.random() in certain circumstances, which is known to be problematic. See https://v8.dev/blog/math-random for details.

How

I removed setting an id on the generated input element, since it's never referred to after being set.

I updated the code to use String(Math.random()) instead of uuid.v4(), in order to get a random string.

(changed per #20477 (comment))

Test Plan

I have copied the built files into node_modules for our Expo Web project, built again, and tested.

Checklist

• Documentation is up to date to reflect these changes (eg: https://docs.expo.dev and README.md).
• Conforms with the Documentation Writing Style Guide
• This diff will work correctly for expo prebuild & EAS Build (eg: updated a module plugin).