Implement metrics for KAS PAT access

What does this MR do and why?

Implement metrics for KAS PAT access. The metrics are sent from KAS with the change from Support Personal Access Tokens in Kubernetes AP... (gitlab-org/cluster-integration/gitlab-agent!1075 - merged)

Refs (Rails) Support Personal Access Token (PAT) aut... (#409028 - closed)

Refs Support Personal Access Token (PAT) authenticat... (gitlab-org/cluster-integration/gitlab-agent#439 - closed)

Epic Support Personal Access Token Authentication fo... (&11235 - closed)

Closes Implement metric for KAS k8s API usage via PAT ... (#422199 - closed)

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