MB-9343 index unaware rebalance via UPR

Change-Id: I3d98d5de5c6dd7d55bff16c946f73b4d07ea4de1
Reviewed-on: http://review.couchbase.org/33337
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>