The offline fallback policy will be removed (#24674)

Author: BethanyZhou

src/KeyVault/KeyVault/ChangeLog.md

@@ -18,6 +18,8 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
+* [Upcoming Breaking Change] Added breaking change warning message for parameter `UseDefaultCVMPolicy` of `Add-AzKeyVaultKey`.
+    - The offline fallback policy will be removed. Key creation will fail if unable to get regional default CVM SKR policy from MAA Service Discovery API.
 * Added parameter `PolicyPath` in `Add-AzKeyVaultCertificate` to support custom policy in the process of certificate enrollment. 
 * Upgraded the API version of merging certificate to 7.5. [#24323]
 

src/KeyVault/KeyVault/Commands/Key/AddAzureKeyVaultKey.cs

@@ -20,6 +20,7 @@
 using Microsoft.Azure.Commands.ResourceManager.Common.ArgumentCompleters;
 using Microsoft.Azure.KeyVault.WebKey;
 using Microsoft.Azure.Management.Internal.Resources.Utilities.Models;
+using Microsoft.WindowsAzure.Commands.Common.CustomAttributes;
 using Microsoft.WindowsAzure.Commands.Utilities.Common;
 
 using System;
@@ -375,6 +376,7 @@ public class AddAzureKeyVaultKey : KeyVaultCmdletBase
             ParameterSetName = ResourceIdCreateParameterSet)]
         public string ReleasePolicyPath { get; set; }
 
+        [CmdletParameterBreakingChangeWithVersion(nameof(UseDefaultCVMPolicy), "12.0.0", "6.0.0", ChangeDescription = "The offline fallback policy will be removed. Key creation will fail if unable to get regional default CVM SKR policy from MAA Service Discovery API.")]
         [Parameter(Mandatory = false,
             ParameterSetName = HsmInteractiveCreateParameterSet,
             HelpMessage = "Specifies to use default policy under which the key can be exported for CVM disk encryption.")]