add code file

Author: lindseymoore

source/connection/connection-pools.txt

@@ -57,7 +57,7 @@ by using either a connection string or ``MongoClientSettings`` object:
   .. tab:: ``MongoClientSettings``
      :tabid: MongoClient
 
-     .. literalinclude:: /includes/fundamentals/code-snippets/mcs.java
+     .. literalinclude:: /includes/fundamentals/code-snippets/ConnectionPool.java
         :start-after: begin MongoSettings
         :end-before: end MongoSettings
         :language: java