Update breaking-changes-messages-help.md (#19029)

Author: isra-fel

documentation/breaking-changes/breaking-changes-attribute-help.md

@@ -36,7 +36,26 @@ All of the attributes have the following common traits:
 The properties "deprecatedByVersion" and "changeInEffectByDate" are information only (for the end user) as of now.
 
 #### Suppress the breaking change messages at runtime
-- If the user desires to not see the warning messages generated by the attributes at runtime, they can set the env variable "SuppressAzurePowerShellBreakingChangeWarnings" to "true".
+
+If the user desires to not see the warning messages generated by the attributes at runtime, they can update the `DisplayBreakingChangeWarning` config as below:
+
+```powershell
+Update-AzConfig -DisplayBreakingChangeWarning $false
+```
+
+This config can be applied to a certain module or cmdlet, allowing the user to suppress breaking change messages just for the chosen part:
+
+```powershell
+Update-AzConfig -DisplayBreakingChangeWarning $false -AppliesTo Az.KeyVault
+```
+
+For more info, run `Get-Help Update-AzConfig`. 
+
+Alternatively, set the env variable "SuppressAzurePowerShellBreakingChangeWarnings" to "true" to suppress all the breaking change messages.
+
+```powershell
+Set-Item Env:\SuppressAzurePowerShellBreakingChangeWarnings "true"
+```
 
 NOTE :
 - The only time you will see the output (at runtime) of an attribute applied to a parameter (property or field) is if the parameter is actually invoked on the cmdline. The breaking change attributes to all parameters that are not invoked are ignored.

documentation/breaking-changes/breaking-changes-messages-help.md

@@ -6,13 +6,13 @@ Breaking change warnings are a means for the cmdlet authors to communicate with
 
 ## How do I get rid of the warnings?
 
-To suppress these warning messages, set the environment variable 'SuppressAzurePowerShellBreakingChangeWarnings' to 'true'.
+To suppress these warning messages, set the config 'DisplayBreakingChangeWarning' to '$false'.
 
-```
-Set-Item Env:\SuppressAzurePowerShellBreakingChangeWarnings "true"
+```powershell
+Update-AzConfig -DisplayBreakingChangeWarning $false
 ```
 
-More details on breaking change message suppression can be found [here](https://github.com/Azure/azure-powershell/blob/preview/documentation/breaking-changes/breaking-changes-attribute-help.md#suppress-the-breaking-change-messages-at-runtime).
+More details on breaking change message suppression can be found [here](https://github.com/Azure/azure-powershell/blob/main/documentation/breaking-changes/breaking-changes-attribute-help.md#suppress-the-breaking-change-messages-at-runtime).
 
 ## Further reading