Improve filenames of JS sampling profiler traces (#53069)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/53069

Changelog: [internal]

This changes the names of the JS traces from Fantom from using a unix timestamp in the file name to using the ISO date:

- From: `View-itest.js-1754406329686.cpuprofile`
- To: `View-itest.js-2025-08-05T15:05:29.686Z.cpuprofile`

Reviewed By: rshest

Differential Revision: D79646760

fbshipit-source-id: d8a654724c1abc2d3e285ee658c2d390d3241d82