[master] Fix a potential concurrentModificationEx in HBase.ClientCache

Author: adela

Summary: Replicating this fix from the swift branch

Test Plan:
wrote a unit test which was failing on ConcurrentModificationException with the old implementation and passing with the new one.

The test adds two clients (HBaseRpc.CLIENTS.getClient(...) checks whether the client is cached - and if not it puts it in the map clients which serves as cache.

The two clients are added in the map and stopClients will throw the exception, the new implementation works fine

Reviewers: manukranthk, gauravm

Reviewed By: manukranthk

CC: hbase-eng@, aaiyer, shaneh

Differential Revision: https://phabricator.fb.com/D864568

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1508977 13f79535-47bb-0310-9956-ffa450edef68
[master] Fix the unit tests: TestHeapSize, TestMetricsMBeanBase and TestStoreFile

Author: liyintang

Summary: Fix the unit tests: TestHeapSize, TestMetricsMBeanBase and TestStoreFile

Test Plan: mvn test

Reviewers: manukranthk, aaiyer

Reviewed By: manukranthk

CC: hbase-eng@

Differential Revision: https://phabricator.fb.com/D906348

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1508978 13f79535-47bb-0310-9956-ffa450edef68
[master] Exclude the replication/avro/rest package from mvn test

Author: liyintang

Summary: Exclude the replication/avro/rest package from mvn test

Test Plan: mvn test

Reviewers: manukranthk

Reviewed By: manukranthk

CC: hbase-eng@

Differential Revision: https://phabricator.fb.com/D906898

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1508979 13f79535-47bb-0310-9956-ffa450edef68