fix: repair example to correct arg index (#761)

Author: rishav-karanjit

Diff for: Examples/runtimes/java/DynamoDbEncryption/src/main/java/software/amazon/cryptography/examples/CreateKeyStoreKeyExample.java

@@ -57,7 +57,7 @@ public static void main(final String[] args) {
         }
         final String keyStoreTableName = args[0];
         final String logicalKeyStoreName = args[1];
-        final String kmsKeyArn = args[1];
+        final String kmsKeyArn = args[2];
         KeyStoreCreateKey(keyStoreTableName, logicalKeyStoreName, kmsKeyArn);
     }
 }