[supply] Save changelog files as version code instead of version name

[joshsnelling]

Google Play expects changelog files to be named for the version code to which they will be applied

Checklist

• I've run bundle exec rspec from the root directory to see all new and existing tests pass
• I've followed the fastlane code style and run bundle exec rubocop -a to ensure the code style is valid
• I've read the Contribution Guidelines
• I've updated the documentation if necessary.

Motivation and Context

This PR fixes #16253

Description

During supply init/setup, downloaded changelog files are named with the version code instead of the version name of the current release. This makes the downloaded changelog file names consistent with what the supply uploader is expecting when uploading to Google Play.

Testing Steps

These changes were tested with an active Google Play release that only had a single APK (and therefore, only a single version code) assigned to it. In theory, these changes should also work for a release that has multiple APKs assigned to it, but I wasn't able to test this scenario.

[joshdholtz]

Great catch! Thanks for fixing this 😊 I appreciate the contribution ❤️

[fastlane-bot]

Hey @joshsnelling 👋

Thank you for your contribution to fastlane and congrats on getting this pull request merged 🎉
The code change now lives in the master branch, however it wasn't released to RubyGems yet.
We usually ship about once a week, and your PR will be included in the next one.

Please let us know if this change requires an immediate release by adding a comment here 👍
We'll notify you once we shipped a new release with your changes 🚀

[fastlane-bot]

Congratulations! 🎉 This was released as part of fastlane 2.146.0 🚀