Alleviate LocalJobRunnerMetricName Conflicts

In some scenarios, Sqoop will use LocalJobRuner (YarnLocal mode) to run a lot of jobs,  assuming  2 million jobs have been run, LocalJobRunner MetricName generated by nextInt function is in the range of (0, 2147483647),
Then the probability of conflict is about 2000/2147483647 = 1/1000, which means that an average of 1 task will fail for every 1000 jobs run.
If LocalJobRunner MetricName is generated by nextLong() whose range is (0, 9223372036854775807), considering that Long's range is 1 billion times that of Int, the probability of a new MetricName conflicts is also reduced by one trillionth times.
the probability of conflict also goes to 1/500000000 from 1/1000. ( under the situation that there are about 200million jobs have been run)