API 2.0: update for Epics is not allowed if you have more than one step flow associated with one state

Issue Summary

When doing an update on an EPIC through PATCH, like the below the call, it will fail if there are 2 process steps associated with the same state :

[
    {
     "op": "replace" ,
     "path": "/state" ,
     "value":  "2"
    }
]

If on the Process Step there the mapping is 1 step to 1 State, this error doesn't happen.

Steps to Reproduce

1. Have a Process Step associated with a Program
2. The Process Step need to have 2 processes associated with the same State
3. Create an Epic and move it to a State on the UI
4. Now try to update the State with a PATCH like the above

Expected Results

TBD by the Product team.

Actual Results

An Error is thrown by the API.

Workaround

To allow the PATCH to work, the Process Step needs to be provided in the PATCH, like:

[
    {
        "op": "replace",
        "path": "/state",
        "value": "1"
    },
    {
        "op": "replace",
        "path": "developmentalStepId",
        "value": "310"
    }
]