(DOCSP-28861): Update Java driver change stream example (#2809)

* (DOCSP-28861): Update Java driver change stream example

* add username and password to connection string

Author: jeff-allen-mongo

source/changeStreams.txt

@@ -373,7 +373,7 @@ upper-right to set the language of the examples on this page.
 
       .. code-block:: java
 
-         MongoClient mongoClient = new MongoClient( new MongoClientURI("mongodb://host1:port1,host2:port2..."));
+         MongoClient mongoClient = MongoClients.create("mongodb://<username>:<password>@<host>:<port>");
 
          // Select the MongoDB database and collection to open the change stream against