fixed couple q tests which failed in recent builds. Need committer review

[Alexander Pivovarov]

HIVE-10665 <https://issues.apache.org/jira/browse/HIVE-10665>
udaf_percentile_approx_23.q

HIVE-10706 <https://issues.apache.org/jira/browse/HIVE-10706>
vectorized_timestamp_funcs.q