R12: Add metrics to measure SLAs

Background

The SLAs (Service Level Agreements) of the Policy Framework are described. The source code must produce metrics so that SLA compliance can be measured.

Purpose

The Policy Framework has Prometheus metrics to measure the performance of REST endpoints for the Policy APIs. Prometheus metrices must be added to measure the performance of ACM REST endpoints and to measure the policy load capabilities of APEX PDP.

Scope

• Enable observability and performance management
• Add Prometheus counters for measuring SLAs on ACM REST endpoints
• Add Prometheus counters for measuring APEX PDP performance SLAs
• Verify that the counters are being produced