fix(api): Declare integration Flow as json.RawMessage

[astefanutti]

Fixes #1590.

Tested with:

$ kamel run --use-flows examples/routes.yaml  

$ kubectl get it routes -o yaml
apiVersion: camel.apache.org/v1
kind: Integration
...
spec:
  flows:
  - from:
      parameters:
        period: "5000"
      steps:
      - set-body:
          constant: Hello Yaml !!!
      - transform:
          simple: ${body.toUpperCase()}
      - to: log:info
      uri: timer:tick

Release Note

fix(api): Declare integration Flow as json.RawMessage

[nicolaferraro]

Thanks!