This object is the value by which an additional adjustment
can be performed on a matched route metric. The actual
operation performed is defined by a3ComRoutePolicyAdjustMetric.
If a3ComRoutePolicyMetric is zero, no metric adjustments are made.
If a3ComRoutePolicyAdjustMetric is set to noop(1) and
a3ComRoutePolicyMetric is a non-zero value, such value will be
unconditionally used as the route metric. Note that the
a3ComRoutePolicyMetric is only used when a3ComRoutePolicyAction is
set to accept(1). If this object is set with a value outside its
scope, which varies depending on a3ComRoutePolicyProtocolType, the
lowest or highest value will be used instead and no error will
be returned. This object can be modified at any time.