Added tests for checking injection metadata

[sydney-tung]

Motivation

This PR was prompted by the addition of new injection metadata fields to telemetry forwarding for python.

Changes

Added new validation checks for injection metadata.

Workflow

1. ⚠️ Create your PR as draft ⚠️
2. Work on you PR until the CI passes (if something not related to your task is failing, you can ignore it)
3. Mark it as ready for review
   • Test logic is modified? -> Get a review from RFC owner. We're working on refining the codeowners file quickly.
   • Framework is modified, or non obvious usage of it -> get a review from R&P team

🚀 Once your PR is reviewed, you can merge it!

🛟 #apm-shared-testing 🛟

Reviewer checklist

• If PR title starts with [<language>], double-check that only <language> is impacted by the change
• No system-tests internal is modified. Otherwise, I have the approval from R&P team
• CI is green, or failing jobs are not related to this change (and you are 100% sure about this statement)
• A docker base image is modified?
  • the relevant build-XXX-image label is present
• A scenario is added (or removed)?
  • Get a review from R&P team

[robertomonteromiguel]

there are ci failures

[robertomonteromiguel]

By default on system-tests pipeline, when you create a PR is going to use the latest released artifacts. You need to force the run for the latest snapshot to activate the tests.
I did that:
Go to the dd-trace-py gitlab pipelines:

https://gitlab.ddbuild.io/DataDog/apm-reliability/dd-trace-py/-/pipelines

Look for the latest main branch pipeline, and click on it. After clicking you will see in the url something like this:

https://gitlab.ddbuild.io/DataDog/apm-reliability/dd-trace-py/-/pipelines/68939911

The latest snapshot identifier for the python tracer OCI image would be: pipeline-68939911

To use it on system-tests you need to run the system-tests docker ssi scenario using the env variable:
DD_INSTALLER_LIBRARY_VERSION=pipeline-68939911

Go to https://gitlab.ddbuild.io/DataDog/system-tests/-/pipelines , select “Run Pipeline” select your branch (INPLAT-652) and add the variables:

• SYSTEM_TESTS_SCENARIOS_GROUPS: DOCKER_SSI
• CI_ENVIRONMENT: dev
• DD_INSTALLER_LIBRARY_VERSION=pipeline-68939911

I launched but it’s failing for python:
https://gitlab.ddbuild.io/DataDog/system-tests/-/pipelines/68950231