Story (Required)

Switch default Argo CD resource tracking behaviour from `label` to `annotation` in Operator

Background and Approach (Required)

In Argo CD 3.0, the default resource tracking is changed from label-based to annotation based tracking[1]. As of now, operator configures `label` based resource tracking if `.spec.resourceTrackingMethod` is not set in ArgoCD CR[2]. Update the operator codebase to use `annotation` based tracking by default. You can find more details about resource tracking in here[3].

[1] https://argo-cd.readthedocs.io/en/latest/operator-manual/upgrading/2.14-3.0/#use-annotation-based-tracking-by-default  

[2] https://github.com/argoproj-labs/argocd-operator/blob/a36e90489c75d7615feb592e853c76a08de80767/controllers/argocd/configmap.go#L237-L248 

 [3]https://argo-cd.readthedocs.io/en/latest/user-guide/resource_tracking/ 

Out of Scope

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Dependencies

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Acceptance Criteria (Mandatory)

• Operator should configure `annotation` based tracking by default
• Documentation is updated to reflect this. 
• Unit/E2E test is added to test the default value for resource tracking.
• Change should not break existing users i.e if  `.spec.resourceTrackingMethod`  is set in ArgoCD CR, this value should be used instead of default. 
• Update release notes of this change.

Definition of Done

• Code Complete:
  • All code has been written, reviewed, and approved.
• Tested:
  • Unit tests have been written and passed.
  • Ensure code coverage is not reduced with the changes.
  • Integration tests have been automated.
  • System tests have been conducted, and all critical bugs have been fixed.
  • Tested and merged on OpenShift either upstream or downstream on a local build.
• Documentation:
  • User documentation or release notes have been written (if applicable).
• Build:
  • Code has been successfully built and integrated into the main repository / project.
  • Midstream changes (if applicable) are done, reviewed, approved and merged.
• Review:
  • Code has been peer-reviewed and meets coding standards.
  • All acceptance criteria defined in the user story have been met.
  • Tested by reviewer on OpenShift.
• Deployment:
  • The feature has been deployed on OpenShift cluster for testing.