[EKS,Helm] Add labels to Datadog service deployment

[Efe-Oddball]

##Description

• Add labels to Datadog service deployments to make future network policies simpler
• https://github.com/department-of-veterans-affairs/vsp-platform-infrastructure/tree/main/terraform/modules/platform-distro
• This is only for Platform v.Next cluster, and not the current live clusters

Acceptance Criteria

• Test to ensure that the labels shows up after the service deployments

Labels:

• service: shared,
• application (Datadog)

Refinement Guidance - Check the following before working on this issue:

• Epic assigned (if needed)
• Estimated (points assigned)
• Sprint assigned (once planned)
• Team member(s) assigned
• Understands how this work aligns with the overall platform