remove NUM_FILES check

    // Since newly initialized empty table has 0 for the parameter.
    if (Long.parseLong(statsParams.get(StatsSetupConst.NUM_FILES)) == 0) {
      return true;
    }

This doesn't look safe; # of files could be set to 0 by an invalid update, or potentially a parallel update that we cannot see (not sure if this is possible; there's some code in metastore that updates basic stats outside of the scope of the query).

It would be better to remove this, and see if it breaks some tests. If we do need this, there should be a negative test at some point