[master] Bug fix to ensure properties in the TableDescriptor don't get overriden during Online Config Change

Author: gauravm

Summary: During testing, I found that certain properties such as the compaction ratio, which were set in the Table Descriptor, were getting overriden when we were trying to do an online configuration change. This diff fixes that.

Test Plan: Improved the TestRegionServerOnlineConfigChange test to cover this case.

Reviewers: aaiyer, adela, manukranthk, rshroff, fan

Reviewed By: fan

CC: hbase-eng@

Differential Revision: https://phabricator.fb.com/D1011438

Task ID: 2842041

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1532841 13f79535-47bb-0310-9956-ffa450edef68