Incorrect values for "RAM Available" and "Max Allowed Quota" are displayed while adding a node with service other than KV or N1QL

While adding a new node for a service (other than KV and N1QL) to a cluster, the value for "RAM Available" and "Max Allowed Quota" are incorrectly calculated. The total displayed RAM is the total of RAM on all the nodes in the cluster.

Steps to reproduce -
1) Create a 2 node cluster with both nodes in the cluster having only KV service.
2) Try adding another node and select a service like search, eventing , cbas or index.
3) The RAM displayed will be the total RAM that is present in the current nodes of the cluster.

As seen in the image attached,
RAM Available 3682MiB Max Allowed Quota 2946MiB
But the actual values should be RAM Available 1841MiB Max Allowed Quota 1472MiB, as the node being added has a RAM of 1.80 GB (approx)