Retrieved service bindings are always returned as a String

[simonkrenger]

Problem

When creating a new service binding, credentials are returned as proper JSON objects:

$ curl -X PUT --user "my_user:my_password" -H'Content-Type: application/json' -d '{ "service_id": "my_id","plan_id": "my_plan_id", "context": { "abc": "xyz"}}' https://mybroker:443/v2/service_instances/1d87d9f9-12c0-4c11-9498-b0d2b7a61e0e/service_bindings/1d87d9f9-12c0-4c11-9498-b0d2b7a61e0e?accepts_incomplete=true
{"preferences":{"dummy":null},"apiVersion":"v1","kind":"Config","clusters":[{[..]

However, if the service binding is retrieved afterwards, the credentials are always returned as an escaped String:

$ curl --user "my_user:my_password" -H'Content-Type: application/json' https://mybroker:443/v2/service_instances/1d87d9f9-12c0-4c11-9498-b0d2b7a61e0e/service_bindings/fa7346bb-938d-42bb-8b44-1139b687824b
{"credentials":"{\"apiVersion\":\"v1\",\"kind\":\"Config\",\"current-context\":\"[..]

I would expect this retrieved binding to be returned as a JSON object as well.