[KeyVault] Fix bug when exception.Response is null (Azure#19558)

* fix bug when exception.Response is null

* add change log

Author: BethanyZhou

src/KeyVault/KeyVault/ChangeLog.md

@@ -18,6 +18,7 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
+* Fixed the exception content swallowed issue when exception.Response is null [#19531]
 
 ## Version 4.7.0
 * Fixed parameter validation logic of `-UseDefaultCVMPolicy`

src/KeyVault/KeyVault/Commands/Certificate/Contact/AddAzureKeyVaultCertificateContact.cs

@@ -110,7 +110,7 @@ public override void ExecuteCmdlet()
                 }
                 catch (KeyVaultErrorException exception)
                 {
-                    if (exception.Response.StatusCode != System.Net.HttpStatusCode.NotFound)
+                    if (exception.Response?.StatusCode != System.Net.HttpStatusCode.NotFound)
                     {
                         throw;
                     }

src/KeyVault/KeyVault/Commands/Certificate/Contact/GetAzureKeyVaultCertificateContact.cs

@@ -93,7 +93,7 @@ public override void ExecuteCmdlet()
             }
             catch (KeyVaultErrorException exception)
             {
-                if (exception.Response.StatusCode != System.Net.HttpStatusCode.NotFound)
+                if (exception.Response?.StatusCode != System.Net.HttpStatusCode.NotFound)
                 {
                     throw;
                 }

src/KeyVault/KeyVault/Commands/Certificate/Contact/RemoveAzureKeyVaultCertificateContact.cs

@@ -110,7 +110,7 @@ public override void ExecuteCmdlet()
                 }
                 catch (KeyVaultErrorException exception)
                 {
-                    if (exception.Response.StatusCode != System.Net.HttpStatusCode.NotFound)
+                    if (exception.Response?.StatusCode != System.Net.HttpStatusCode.NotFound)
                     {
                         throw;
                     }

src/KeyVault/KeyVault/Commands/Certificate/Policy/GetAzureKeyVaultCertificatePolicy.cs

@@ -86,7 +86,7 @@ public override void ExecuteCmdlet()
             }
             catch (KeyVaultErrorException exception)
             {
-                if (exception.Response.StatusCode != System.Net.HttpStatusCode.NotFound)
+                if (exception.Response?.StatusCode != System.Net.HttpStatusCode.NotFound)
                 {
                     throw;
                 }