Review and enhance tracing support for ad service service (Java)

[cartersocha]

The following is a list of requirements that we need to evaluate before declaring v1 for trace telemetry. These requirements are across the entire application; Not all services will meet all requirements. Determine the relevant features for this service.

• Automatic Instrumentation is being used where appropriate.
• Library instrumentation is being used if automatic instrumentation is unavailable.
• Services extend automatic instrumentation.
  • New attributes/events attached to existing spans.
  • New spans are being created from existing spans.
• Automatic and Manual Context Propagation are being demonstrated.
• Telemetry is not being sampled upfront.
• Telemetry is not being filtered upfront.
• Baggage is being set and read appropriately (i.e., baggage must be explicitly set as attributes on spans)
• Update the centralized tracing doc

Referencing: #42

Dependent on this item: #40

[cartersocha]

Tracing is code complete