Update test_proxy_migration_guide.md (Azure#21795)

* Update test_proxy_migration_guide.md

* Update doc/dev/test_proxy_migration_guide.md

Co-authored-by: Scott Beddall <45376673+scbedd@users.noreply.github.com>

Co-authored-by: Scott Beddall <45376673+scbedd@users.noreply.github.com>

Author: Rakshith Bhyravabhotla

doc/dev/test_proxy_migration_guide.md

@@ -135,6 +135,11 @@ made to `https://fakeendpoint-secondary.table.core.windows.net`, and URIs will a
 
 For more details about sanitizers and their options, please refer to [devtools_testutils/sanitizers.py][py_sanitizers].
 
+### Enabling Testproxy on the CI
+
+To enable test proxy on the CI, you need to set the parameter `TestProxy: true` on ci.yml and on tests.yml are present in the service level folder.
+
+![image](https://user-images.githubusercontent.com/45376673/142270668-5be58bca-87e5-45f5-b593-44f8b1f757bc.png)
 ### Record test variables
 
 To run recorded tests successfully when there's an element of non-secret randomness to them, the test proxy provides a