(Azure CXP) Azure does not support AES256

Added this note: 'Azure Web Apps does **not** support AES256 and all pfx files should be encrypted with TrippleDES. Based on customer feedback: https://github.com/MicrosoftDocs/azure-docs/issues/45896

Author: Grace-MacJones-MSFT

articles/app-service/configure-ssl-certificate.md

@@ -33,6 +33,9 @@ To follow this how-to guide:
 
 ## Private certificate requirements
 
+> [!NOTE]
+> Azure Web Apps does **not** support AES256 and all pfx files should be encrypted with TrippleDES.
+
 The [free App Service Managed Certificate](#create-a-free-certificate-preview) or the [App Service certificate](#import-an-app-service-certificate) already satisfy the requirements of App Service. If you choose to upload or import a private certificate to App Service, your certificate must meet the following requirements:
 
 * Exported as a [password-protected PFX file](https://en.wikipedia.org/w/index.php?title=X.509&section=4#Certificate_filename_extensions)