[DOCS] Update to the workaround for IMPALA-3316
[DOCS] Update to the workaround for IMPALA-3316

Both the date and time strings can be stored and converted to TIMESTAMP

Change-Id: If45da5d24dd3bc5f649d95b5bc104047420dbea1
Reviewed-on: http://gerrit.cloudera.org:8080/10800
Reviewed-by: Csaba Ringhofer <228bc1e8f2429c3aceee4c98731559aa0ec396d0@cloudera.com>
Tested-by: Impala Public Jenkins <039b6b20426ff68ebe492b3021890d8c8fd010c9@cloudera.com>

cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala