{Security} az security api-collection apim onboard/offboard: Fix the documentation (#30716)

* Update _onboard.py

Fix example

* Update _offboard.py

Author: aditdalvi

src/azure-cli/azure/cli/command_modules/security/aaz/latest/security/api_collection/apim/_offboard.py

@@ -18,6 +18,9 @@
 )
 class Offboard(AAZCommand):
     """Offboard an Azure API Management API from Microsoft Defender for APIs. The system will stop monitoring the operations within the Azure API Management API for intrusive behaviors.
+
+    :example: Onboard an Azure API Management API to Microsoft Defender for APIs.
+        az security api-collection apim offboard --resource-group MyResourceGroup --service-name MyApiManagementServiceName --api-id echo-api
     """
 
     _aaz_info = {

src/azure-cli/azure/cli/command_modules/security/aaz/latest/security/api_collection/apim/_onboard.py

@@ -19,7 +19,7 @@ class Onboard(AAZCommand):
     """Onboard an Azure API Management API to Microsoft Defender for APIs. The system will start monitoring the operations within the Azure Management API for intrusive behaviors and provide alerts for attacks that have been detected.
 
     :example: Onboard an Azure API Management API to Microsoft Defender for APIs.
-        az security api-collections create --resource-group MyResourceGroup --service-name MyApiServiceName --api-id EchoApi
+        az security api-collection apim onboard --resource-group MyResourceGroup --service-name MyApiManagementServiceName --api-id echo-api
     """
 
     _aaz_info = {