style(pdk): rename some variables

[chronolaw]

Summary

KAG-6036
It is a follow up of #14025

Checklist

• The Pull Request has tests
• A changelog file has been created under changelog/unreleased/kong or skip-changelog label added on PR if changelog is unnecessary. README.md
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Issue reference

Fix #[issue number]

[team-gateway-bot]

Cherry-pick failed for master, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git remote add upstream https://github.com/kong/kong-ee
git fetch upstream master
git worktree add -d .worktree/cherry-pick-14063-to-master-to-upstream upstream/master
cd .worktree/cherry-pick-14063-to-master-to-upstream
git checkout -b cherry-pick-14063-to-master-to-upstream
ancref=$(git merge-base 0ebc358063569cb08bba8e8bdf1586c2146ed9a0 11e3ec40d292a4a385f988d52f47de4170ba4104)
git cherry-pick -x $ancref..11e3ec40d292a4a385f988d52f47de4170ba4104

[chronolaw]

cherry-pick is blocked by https://github.com/Kong/kong-ee/pull/11082

[team-gateway-bot]

Successfully created cherry-pick PR for master:

• https://github.com/kong/kong-ee/pull/11085