The value of tRPOperPSAcptActnMetricSource indicates the source
of the accept action metric.
The value 'igpCost(1)' means that the value of MED (Multi Exit
Discriminator) or the metric value is derived from the IGP
(Interior Gateway Protocol) cost of the route and the value of
the object tRPOperPSAcceptActionMetricValue is ignored.
The value 'metricVal(2)' means the metric value is the value of
tRPOperPSAcceptActionMetricValue.