HDDS-4526. Remove false-positive error logs from LeaseManager

[elek]

What changes were proposed in this pull request?

There is an error log which can be seen frequently in the log:

2020-11-30 15:35:58,539 [CommandWatcher-LeaseManager#LeaseMonitor] ERROR lease.LeaseManager (LeaseManager.java:run(238)) - Execution was interrupted 
java.lang.InterruptedException: sleep interrupted
	at java.lang.Thread.sleep(Native Method)
	at org.apache.hadoop.ozone.lease.LeaseManager$LeaseMonitor.run(LeaseManager.java:234)
	at java.lang.Thread.run(Thread.java:748)

This log is introduced by HDDS-2561 to make Sonar happy, but it was not required as LeaseManager use the thread interrupt intentionally.

For a proper fix we can keep the logging on WARN level AND replace thread interrupts with thread notify/wait.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-4526

How was this patch tested?

Unit test. TestLeaseManager has good coverage.

[adoroszlai]

LGTM.

[adoroszlai]

Thanks @elek for fixing this.