When a flow is added to another flow and there is
a decider placed on that link we need to make sure
that we retain that decider.
This also ensures that any predecessor of that flow
that has a decider that affects the flow nodes execution
also gets used in the decision process.
Closes-Bug: #1515748
Change-Id: Ifdf20378b26cdd13e0a3ff87cec8990fe89c0661