[AppService]: fix #9316-Calling Set-AzWebApp with -HostNames can fail but returns an un-catchable warning that only indicates BadRequest (#15639)

* Fix #9316 - Calling Set-AzWebApp with -HostNames can fail will returns an catchable warning with proper error descreption.

* Updated changelog.md

* Update ChangeLog.md

Co-authored-by: Yabo Hu <[email protected]>

Author: Kotasudhakarreddy

src/Websites/Websites/ChangeLog.md

@@ -18,6 +18,8 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
+* Fixed `Set-AzWebApp` to return a valid warning message when fails to add -Hostname #9316
+* Fixed `Get-AzWebApp` to return CustomDomainVerificationId in the response. #9316
 
 ## Version 2.8.1
 * Fixed `Add-AzWebAppAccessRestrictionRule` failing when users does not have permissions to get Service Tag list #15316 and #14862

src/Websites/Websites/Models.WebApp/PSSite.cs

@@ -62,7 +62,8 @@ public PSSite(Site other)
                   suspendedTill: other.SuspendedTill,
                   slotSwapStatus: other.SlotSwapStatus,
                   httpsOnly: other.HttpsOnly,
-                  identity: other.Identity
+                  identity: other.Identity,
+                  customDomainVerificationId: other.CustomDomainVerificationId
                   )
         {
             PropertyInfo AzureStoragePathProp = other.GetType().GetProperty("AzureStoragePath");

src/Websites/Websites/Utilities/WebsitesClient.cs

@@ -161,9 +161,9 @@ public void AddCustomHostNames(string resourceGroupName, string location, string
                         }
                     }
                 }
-                catch (Exception e)
+                catch (DefaultErrorResponseException e)
                 {
-                    WriteWarning("Could not set custom hostname '{0}'. Details: {1}", hostName, e.ToString());
+                    WriteWarning("Could not set custom hostname '{0}'. Details: {1}", hostName, e?.Response?.Content?.ToString());
                     return;
                 }
             }