Pass Variables to Flows through Start Flow Action

[swolfsohn]

When using the Start Flow action (https://docs.microsoft.com/en-us/connectors/flowmanagement/#startflow), it would be useful to be able to pass variables to flows that have inputs. 

This is similar to another idea (https://powerusers.microsoft.com/t5/Flow-Ideas/Variable-for-pass-from-a-flow-run-to-next-flow-run/id...) but rather than passing variables between runs of the same flow, I am specifically asking for one flow to be able to pass variables to any flow called using the Start Flow action.