[pkg/otlp] Make hostname logic consistent with exporter

[mx-psi]

What does this PR do?

Use preview hostname resolution for the Datadog Agent, to make it consistent with the logic from the Datadog exporter. This relates to open-telemetry/opentelemetry-collector-contrib/issues/10424

Motivation

Consistency across products. Ignore container id when getting hostname.

Describe how to test/QA your changes

• Send OTLP metrics with container.id set in the resource attribute. Check that the hostname on these metrics is not that value, but rather the one resolved by the Agent
• Send OTLP traces with container.id set in the resource attribute. Check that the hostname on these metrics is not that value, but rather the one resolved by the Agent

Reviewer's Checklist

• If known, an appropriate milestone has been selected; otherwise the Triage milestone is set.
• Use the major_change label if your change either has a major impact on the code base, is impacting multiple teams or is changing important well-established internals of the Agent. This label will be use during QA to make sure each team pay extra attention to the changed behavior. For any customer facing change use a releasenote.
• A release note has been added or the changelog/no-changelog label has been applied.
• Changed code has automated tests for its functionality.
• Adequate QA/testing plan information is provided if the qa/skip-qa label is not applied.
• At least one team/.. label has been applied, indicating the team(s) that should QA this change.
• If applicable, docs team has been notified or an issue has been opened on the documentation repo.
• If applicable, the need-change/operator and need-change/helm labels have been applied.
• If applicable, the k8s/<min-version> label, indicating the lowest Kubernetes version compatible with this feature.
• If applicable, the config template has been updated.

[ajgajg1134]

Looks good for APM

[jtappa]

tiny edit, approving so I'm not blocking on release note