The value of tRPAdminPSAcptActnMetricSource specifies the source
of the accept action metric.
When the value of tRPAdminPSAcptActnMetricSource is set to
'igpCost(1)' the value of tRPAdminPSAcceptActionMetricValue is
ignored and the value of MED (Multi Exit Discriminator) or the
metric value is derived from the IGP (Interior Gateway Protocol) cost
of the route.
The default value of tRPAdminPSAcptActnMetricSource is
'metricVal(2)' which means the metric value is the value of
tRPAdminPSDefaultActionMetricValue.