add_priority_str

Adds a priority map entry into either the NMSettingVlan:ingress_priority_map or the NMSettingVlan:egress_priority_map properties.

The priority map maps the Linux SKB priorities to 802.1p priorities.

Parameters:

this	the SettingVlan
map	the type of priority map
str	the string which contains a priority map, like "3:7"

Returns:

true if the entry was successfully added to the list, or it overwrote the old value, false if error