Add session and runner id to list of telemetry items (#39733)

* Add session and runner id to list of telemetry items

* Update unit-testing-mstest-runner-telemetry.md

Author: nohwnd

docs/core/testing/unit-testing-mstest-runner-telemetry.md

@@ -74,6 +74,8 @@ The telemetry feature collects the following data points:
 | All | Version of the platform. |
 | All | Version of your extensions. |
 | All | Version of your test adapter. |
+| All | Guid to correlate events from a single runner. |
+| 1.0.3 | Guid to correlate events from a single test run. |
 
 ## Continuous integration detection