Fix/ads placement default

[amandascm]

What is the purpose of this pull request?

Consider a possible null value for the sponsoredProducts query parameter placement and apply the default value ads_newtail before making the proper ad request (previous implementation only covered potential undefined placement, which led to "null" string accepted as a defined value).

Types of changes

• New feature (non-breaking change which adds functionality)
• Refactor (non-breaking change which doesn't change any functionalities)
• Bug fix (non-breaking change which fixes an issue)
• Chore (changes configuration files, GitHub workflows, etc.)
• Breaking change (fix or feature that would cause existing functionality to change)
• Requires change to documentation, which has been updated accordingly.

[vtex-io-ci-cd]

Hi! I'm VTEX IO CI/CD Bot and I'll be helping you to publish your app! 🤖

Please select which version do you want to release:

• Patch (backwards-compatible bug fixes)

• Minor (backwards-compatible functionality)

• Major (incompatible API changes)

And then you just need to merge your PR when you are ready! There is no need to create a release commit/tag.

• No thanks, I would rather do it manually 😞

[vtex-io-docs-bot]

Beep boop 🤖

I noticed you're not using the Docs Builder properly yet, if you need help to set that up please go to IO Documentation

[diegopgcabral]

Great!!

[vtex-io-ci-cd]

Your PR has been merged! App is being published. 🚀
Version 2.10.4 → 2.10.5

After the publishing process has been completed (check #vtex-io-releases) and doing A/B tests with the new version, you can deploy your release by running:

vtex deploy vtex.adserver-resolver@2.10.5

After that your app will be updated on all accounts.

For more information on the deployment process check the docs. 📖