[CX] Majority of analytics info log is MaintainDcpCallbackFactory DCP state dumps

In a recent QE reported issue (MB-28887) where we are unable to determine the start of a problem due to log rollover, over 141MB out of 244 MB log are 4086 instances of:

2018-03-23T22:48:52.651-07:00 INFO CBAS.metadata.MaintainDcpCallbackFactory [Executor-240:8800eb0ca0e77c7859db50c99b6ea7da] The DCP state written to {"class":LSMBTreeWithBloomFilterDiskComponent", "index":{"class":"DiskBTree","file":"storage/partition_0/Default/ds4/0/ds4/2018-03-23-22-48-52-616_2018-03-23-22-48-52-616_b"}} is ...

This is way too much logging.  We need to either reduce this to DEBUG, or figure out how to greatly reduce the size of these logs.  Were we to log an array instead of map, that would help a tiny bit, but still it will be way too much to appear in the product log.