Update ConnectionPoolMetrics documentation

Author: injectives

driver/src/main/java/org/neo4j/driver/ConnectionPoolMetrics.java

@@ -58,9 +58,9 @@ public interface ConnectionPoolMetrics
     int creating();
 
     /**
-     * A counter to record how many connections have been successfully created with this pool since the pool is created.
+     * A counter to record how many connections have been successfully created with this pool since the pool was created.
      * This number increases every time when a connection is successfully created.
-     * @return The amount of connections that has ever been created by this pool.
+     * @return The amount of connections that have ever been created by this pool.
      */
     long created();