The value of tRPOperPSDefActnAigpMetricVal indicates the value to
be added or set for the route AIGP(Accumulated IGP) metric.
When the value of tRPOperPSDefActionAigpMetric is set to 'none(1)'
or 'useIgp(4)', the value of tRPOperPSDefActnAigpMetricVal is
ignored.