Fix sample extension

The sample extension has not been updated since we made some changes to the underlying transport. Should be fairly simple and could facilitate more external extension interactions.

Locate the sample extension and compare it with the updated underlying transport before deciding which integration points are outdated. Confirm the current extension-provider flow and identify the external extension interactions the sample should support. Done means the sample works with the current transport and demonstrates those interactions.

Written by the indexing model from the issue text.