Disable finatra controller spans by default

[jaydeluca]

Was working through this as part of #14096 and noticed that these controller spans aren't behind the experimental controller flag like the others.

Changelog Info:

By default, the Java agent suppresses controller spans unless enabled via the otel.instrumentation.common.experimental.controller-telemetry.enabled system property. The Finatra instrumentation was not adhering to this, and has been updated to now require the configuration flag in order to enable controller spans.

Set otel.instrumentation.common.experimental.controller-telemetry.enabled=true in order to re-enable the generation of these controller spans.

[github-actions]

⚠️ Breaking Change Documentation Required

This PR has been labeled as a breaking change. Please ensure you provide the following information:

Migration Notes Required

Please add detailed migration notes to help users understand:

• What is changing and why
• How to update their code/configuration
• Any alternative approaches if applicable
• Code examples showing before/after usage

Checklist

• Migration notes added to the PR description
• Breaking change is documented in the changelog entry for the next release
• Consider if this change requires a major version bump

Your migration notes will be included in the release notes to help users upgrade smoothly. The more detailed and helpful they are, the better the user experience will be.

---

This comment was automatically generated because the breaking change label was applied to this PR.