Error while running from tile

[apandura-tibco]

Steps to reproduce:

1. Have a rest activity which has a GET request to "https://jsonplaceholder.typicode.com/todos"
2. Run the whole flow and see for flow completion message
3. Select the rest activity and open the debug panel
4. Start the flow test runner from this tile.

You should see the above error message.

Reason / Additional information:
In this case, all the debug inputs of the activity are set to null. When we try to retest the flow from this tile, the payload for POST http://localhost:3303/api/v2/runner/processes/restart is :

initialState: {...}
interceptor: {
  tasks: [{
    id: "rest_2"
    inputs: {
      pathParams: null,
      queryParams: null,
      headers: null,
      content: null
    }
  }]
}

The step is failing with the provided intercepted input data.

I have noticed that we can fix this with the following payload to the restart call:

initialState: {...}
interceptor: {
  tasks: [{
    id: "rest_2"
    inputs: {}
  }]
}

So I think if we can exempt all null inputs (which is formed by the angular form), we can solve such issues.

But what if the user wants to provide a null value for debugging that step?