Updated ion java to most recent version to avoid security vulnerabilities

Author: Brendan Lynch

pom.xml

@@ -309,7 +309,7 @@
         <dependency>
             <groupId>software.amazon.ion</groupId>
             <artifactId>ion-java</artifactId>
-            <version>1.5.1</version>
+            <version>1.11.4</version>
         </dependency>
         <dependency>
             <groupId>software.amazon.glue</groupId>