Its getting update same definition row itself. its not creating sperate row for activate business rule so that business rule is not visible in powerapps.
private void ActivateWorkflow(IOrganizationService organizationService, Guid _workflowId)
{
var activateRequest = new SetStateRequest
{
EntityMoniker = new EntityReference
(Workflow.EntityLogicalName, _workflowId),
State = new OptionSetValue((int)WorkflowState.Activated),
Status = new OptionSetValue((int)workflow_statuscode.Activated)
};
organizationService.Execute(activateRequest);
}