DRILL-1384: Part 2 - Unit test cases change.
Change two JDBC test cases, since the results for query w/o ORDER BY are not semantically deterministic.
Make sure TestHashJoinAdvanced uses HashJoin only. Modify expected results in TestProjectPushDown: the order of pushed columns could be different.
Disable TPCH Q16, due to OPTIQ-373 plan change.
Disable one parquet writer in TestExample, since it need ensure the created file does not exist on the file system.
