A textual name for the APS group which this channel is
included in. If the channel is not part of an APS group
this value is set to a string of size 0.
When an instance of cApsChanConfigIfIndex is set
equal to an instance of cApsMapIfIndex,
cApsMapGroupName is set equal to the corresponding
value of cApsChanConfigGroupName.
If the cApsMapIfIndex ceases to be equal to an
instance of cApsChanConfigIfIndex, either because
of a change in the value of cApsChanConfigIfIndex,
or because of row deletion in the CApsChanConfigTable,
cApsMapGroupName is set to a string of size 0.