Description of problem:
When using the `from dockerfile` add flow, there are 2 similar fields that are used to specify which port the application is listening on:

dockerfile -> container port

route -> target port

No matter what value is entered for the `target port`, it is never persisted anywhere.

It seems like


Steps to Reproduce

    go to +Add => `from dockerfile`
    Enter git URL https://github.com/rohitkrai03/flask-dockerfile-example
    Enter docker container port 5000
    open routing advanced options
    Enter target port 1234
    Complete form


Actual results:
Service is created with port equal to container port.

No where in the deployment or service is the target port 1234 used.


Expected results:
Container port and target port are the same thing in the form and therefore should be treated as such. They should probably share the same value in the form data.


Reproducibility (Always/Intermittent/Only Once):
always


Build Details:
4.6.0-0.nightly-2020-09-16-062819