Actually accept String expressions for "prefetch" and "receive-timeout" in jms namespace

Issue: SPR-10986
(cherry picked from commit ccafccb)

Author: jhoeller

spring-jms/src/main/java/org/springframework/jms/config/JmsListenerContainerParser.java

@@ -154,14 +154,14 @@ else if ("simple102".equals(containerType)) {
 		String prefetch = containerEle.getAttribute(PREFETCH_ATTRIBUTE);
 		if (StringUtils.hasText(prefetch)) {
 			if (containerType.startsWith("default")) {
-				containerDef.getPropertyValues().add("maxMessagesPerTask", new Integer(prefetch));
+				containerDef.getPropertyValues().add("maxMessagesPerTask", prefetch);
 			}
 		}
 
 		String receiveTimeout = containerEle.getAttribute(RECEIVE_TIMEOUT_ATTRIBUTE);
 		if (StringUtils.hasText(receiveTimeout)) {
 			if (containerType.startsWith("default")) {
-				containerDef.getPropertyValues().add("receiveTimeout", new Integer(receiveTimeout));
+				containerDef.getPropertyValues().add("receiveTimeout", receiveTimeout);
 			}
 		}