set exec mode batch

Author: luca-p-castelli

e2e-tests/data/batch-job-cr.yaml

@@ -78,6 +78,7 @@ spec:
   job:
     jarURI: local:///opt/flink/usrlib/myjob.jar
     entryClass: org.apache.flink.streaming.examples.wordcount.WordCount
+    args: ["--execution-mode", "BATCH"]
     parallelism: 2
     upgradeMode: stateless
   mode: native