Unable to remove 'kv' service using topology param

Build: 8.0.0-1702

Steps:

• 2 node cluster both running only KV service
• Add index service on node 172.23.108.70 using the command,

  curl -X POST 172.23.108.69:8091/controller/rebalance -d "knownNodes=ns_1@172.23.108.69,ns_1@172.23.108.70" -d "topology[index]=ns_1@172.23.108.70" -d "topology[kv]=ns_1@172.23.108.69"

Observation:

At the end of this, index is added to .70 node, but KV was not removed from the service

Expectation:

KV service should be removed from that node.

Even the ns_server log in the UI suggests the same,

Starting rebalance, KeepNodes = ['ns_1@172.23.108.69','ns_1@172.23.108.70'], EjectNodes = [], Failed over and being ejected nodes = []; no delta recovery nodes; Operation Id = 9c382bd496f40b8d1f9b2bb28290499a;DesiredServiceNodes = #{index => ['ns_1@172.23.108.70'], kv => ['ns_1@172.23.108.69']}