[azure_metrics] Add available memory percentage metric

[zmoog]

Proposed commit message

[azure_metrics] Add available memory percentage metric

What does this PR do?

Adds the Azure Monitor Available Memory Percentage metric alongside Available Memory Bytes for the compute_vm and compute_vm_scaleset data streams.

Also adds exported field metadata, updates _dev/build/docs/README.md, and regenerates the rendered docs.

Checklist

• I have run elastic-package check locally

How to test this PR locally

cd packages/azure_metrics
elastic-package check

Note: elastic-package check reports existing skipped dashboard validation warnings (SVR00002).

[github-actions]

⚠️ Package docs validation failed. Please check the workflow run for details.

For support, reach out in the #docs Slack channel.

cc @elastic/integration-docs

[github-actions]

✅ Elastic Docs Style Checker (Vale)

No issues found on modified lines!

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[elastic-vault-github-plugin-prod]

✅ All changelog entries have the correct PR link.

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 48a956e

History

• 💚 Build #44151 succeeded 66d57a0
• 💚 Build #44146 succeeded 360b058

[zmoog]

Quick check to see if we're getting the new azure.compute_vm.available_memory_percentage field:

[elastic-vault-github-plugin-prod]

Package azure_metrics - 1.14.0 containing this change is available at https://epr.elastic.co/package/azure_metrics/1.14.0/