To query just the calls dialed by Outbound Dialing you need to add the dimension for the contact list (since that is the main difference between manual dials by the agent and automatic dials by Genesys Cloud).
So, in the parameters add;
{
"type": "dimension",
"dimension": "outboundContactListId",
"operator": "exists"
},------------------------------
George Ganahl GCP (PureCloud), ICCE
Principal Technology Consultant
Genesys
------------------------------