Added a healthcheck to the OpenTelemetry Collector container

[martinjt]

Adds an internal healthcheck to the Collector container. This uses a non-default port, and adds a new extension so it doesn't interfere with any components the user has specified. This also enables the "merge and append" feature flag.

PR Checklist

• Created a feature/dev branch in your fork (vs. submitting directly from a commit on main)
• Based off latest main branch of toolkit
• PR doesn't include merge commits (always rebase on top of our main, if needed)
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Contains NO breaking changes
• Every new API (including internal ones) has full XML docs
• Code follows all style conventions

[Copilot]

Pull Request Overview

This PR adds an internal health check capability to the OpenTelemetry Collector container, providing better monitoring and status visibility within the Aspire dashboard. The implementation uses a dedicated non-default port and configurable extension to avoid conflicts with user-specified components.

• Adds a new DisableHealthcheck setting to allow users to opt out of the health check functionality
• Implements health check endpoint configuration on port 13233 with the /health path
• Enables the "merge and append" feature flag for OpenTelemetry Collector configuration

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
OpenTelemetryCollectorSettings.cs	Adds DisableHealthcheck property to control health check behavior
OpenTelemetryCollectorExtensions.cs	Implements health check endpoint configuration and feature flag enablement

[martinjt]

Needs tests and some other stuff by the looks of it, I'll sort those tomorrow.

[aaronpowell]

Wanna add a test on this?

I should have read comments first 😅