Adding a minor validation in Message to ensure partition key is same …

…as sessionid. (#10612)

If sessionid is set on a message, then partition key should be same as sessionid. For some customers using sessions, partition key was not at all in the broker and some operations started failing as service bus service assumes partition key will be same as session key. It validates partition key now.

sdk/servicebus/microsoft-azure-servicebus/src/main/java/com/microsoft/azure/servicebus/Message.java

@@ -230,6 +230,7 @@ public String getSessionId() {
     @Override
     public void setSessionId(String sessionId) {
         this.sessionId = sessionId;
+        this.partitionKey = sessionId;
     }
 
     @Override
@@ -321,6 +322,11 @@ public String getPartitionKey() {
 
     @Override
     public void setPartitionKey(String partitionKey) {
+    	if (this.sessionId != null && !this.sessionId.equals(partitionKey))
+    	{
+    		// SessionId is set. Then partition key must be same as session id.
+    		throw new IllegalArgumentException("PartitionKey:" + partitionKey +" is not same as SessionId:" + this.sessionId);
+    	}
         this.partitionKey = partitionKey;
     }