[ad] rename adService to ad

[Sozhan308]

Changes

Renames adservice to ad.

This is part of the ongoing renaming for standarizing the component names

Merge Requirements

For new features contributions, please make sure you have completed the following
essential items:

• CHANGELOG.md updated to document new feature additions
• Appropriate documentation updates in the docs
• Appropriate Helm chart updates in the helm-charts

Maintainers will not merge until the above have been completed. If you're unsure
which docs need to be changed ping the
@open-telemetry/demo-approvers.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Sozhan308 / name: Sozhan Natarajan (0edb6b5, 2c5397a, 8f85d05, a030e10, 6d61d40)
• ✅ login: puckpuck / name: Pierre Tessier (ce335ca, d593e85, e1706f7)
• ✅ login: julianocosta89 / name: Juliano Costa (51f3e5c)

[puckpuck]

Can you add a Changelog entry to this?

[Sozhan308]

Can you add a Changelog entry to this?

I have updated the changelog

[puckpuck]

I updated this PR, to update the environment variable AD_SERVICE_* -> AD_* and the feature flag names.

After the changes, I tested it, and Jaeger displayed traces as expected.

[Sozhan308]

I updated this PR, to update the environment variable AD_SERVICE_* -> AD_* and the feature flag names.

After the changes, I tested it, and Jaeger displayed traces as expected.

Thank you for updating and testing the changes, @puckpuck. Being new to this project, it took me some time to set it up locally to test the changes. I would also like to learn more about the project and explore opportunities to contribute to other topics. Would it be okay if I reach out to you, @puckpuck, to learn more about the project and its ongoing discussions?

[julianocosta89]

Added some nits but LGTM