[master] Remove most of TestHeapSize

Author: elliott

Summary: Most of TestHeapSize is useless.  I just left the parts that I thought were actually used a lot in memory accounting.

Test Plan: mvn clean test -Dtest=TestHeapSize

Reviewers: adela

Reviewed By: adela

CC: hbase-eng@

Differential Revision: https://phabricator.fb.com/D1300578

Task ID: 4222728

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1591722 13f79535-47bb-0310-9956-ffa450edef68