[HBASE-8805] Added a test to verify that the compaction properties behave as expected when changed online

Author: gauravm

Summary: I wanted to verify that the compaction properties when changed online, behave as expected, and cause a change in the compaction algorithm (and not only test if the values are changing. Previous tests were geared towards that).

Test Plan: Unit Test

Reviewers: aaiyer, liyintang, adela, fan, manukranthk, rshroff, arjen

Reviewed By: fan

CC: hbase-eng@

Differential Revision: https://phabricator.fb.com/D1031643

Task ID: 2842041

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1537574 13f79535-47bb-0310-9956-ffa450edef68