Fix ExtensionRole

Author: huangpf

src/ServiceManagement/Compute/Commands.ServiceManagement/Extensions/Common/ExtensionRole.cs

@@ -65,6 +65,7 @@ public string GetExtensionId(string extensionName, string slot, int index)
         {
             var normalizedExtName = extensionName.Replace(".", string.Empty);
             normalizedExtName = normalizedExtName.Replace(" ", string.Empty);
+            normalizedExtName = normalizedExtName.Replace("_", string.Empty);
 
             var suffix = new StringBuilder();
             suffix.AppendFormat(ExtensionIdSuffixTemplate, normalizedExtName, slot, index);