Convert "Invalid operation while connection is closing" to retriable ServiceBusException. (Azure#17023)

* add retriable exception

* add helper class to AmqpExceptionHelper.GetClientException

Author: DorothySun216

sdk/servicebus/Microsoft.Azure.ServiceBus/src/Amqp/AmqpExceptionHelper.cs

@@ -215,6 +215,9 @@ public static Exception GetClientException(Exception exception, string reference
                 case TimeoutException _:
                     return new ServiceBusTimeoutException(message, aggregateException);
 
+                case InvalidOperationException ex when ex.Message.IndexOf("connection is closing", StringComparison.OrdinalIgnoreCase) != -1:
+                    return new ServiceBusException(true, aggregateException);
+
                 case InvalidOperationException _ when connectionError:
                     return new ServiceBusCommunicationException(message, aggregateException);
             }

sdk/servicebus/Microsoft.Azure.ServiceBus/src/Core/MessageReceiver.cs

@@ -1486,7 +1486,7 @@ async Task DisposeMessagesAsync(IEnumerable<Guid> lockTokens, Outcome outcome)
 
                     throw new MessageLockLostException(Resources.MessageLockLost);
                 }
-
+                
                 throw AmqpExceptionHelper.GetClientException(exception);
             }
         }