Add Service Wizard corrupts the zookeeper config for existing Storm service

STR:
1. On a cluster with Storm already installed, run Add Service Wizard to install an additional service not already part of the cluster (say, Falcon, but it doesn't matter which service).
2. Try to restart Storm. Nimbus/Supervisor will not be able to start

Note that adding Storm itself via Add Service Wizard works fine.
This corruption happens when adding a non-Storm service.

The reason is Add Service Wizard updates storm-site and in doing so, corrupts storm.zookeeper.servers property.

Before running Add Service Wizard:

storm.zookeeper.servers: "['c6401.ambari.apache.org','c6402.ambari.apache.org','c6403.ambari.apache.org']"

After completing Add Service Wizard to add another service:

storm.zookeeper.servers: "'['c6401.ambari.apache.org','c6402.ambari.apache.org','c6403.ambari.apache.org']'",

After completing Add Service Wizard again to add another service:

storm.zookeeper.servers: "''['c6401.ambari.apache.org','c6402.ambari.apache.org','c6403.ambari.apache.org']''",

Note that every time Add Service Wizard runs, extra single quotes are added around the ZK array.

Workaround
After running Add Service Wizard, go to Services > Storm > Config and hit Save. This fixes storm.zookeeper.servers and Nimbus/Supervisors will be able to start.