BUG 2187 - Persisting shard list in ShardManager

BUG 2187 - Persisting shard list in ShardManager

In ShardManager, the local shard list is persisted as a snapshot.
On recovery, persisted shard list is used to create the shards.
During recovery, obtained persisted information is updated to the
configuration so that it is uniformly available to the DatastoreContext.

Incorporated the comments

Also, as localShards are now created after RecoveryCompletion, the
shardManager mbean is associated with the shardManager immediately
after creation. On creating the localShards, the shards addition
is notified to the mbean object.
In the shardManagerTests involving verification of the syncStatus
and CountDownLatch objects, the testcases are made to wait for
localShard creation by waiting for recoveryCompletion message.

Change-Id: I523ed9b14af4b1b6e272f05faac1cf37abfef336
Signed-off-by: kalaiselvik <Kalaiselvi_K@Dell.com>