When the result of the CNI ADD for the cluster default network features multiple interfaces, all are reported w/ `default: true`

The CreateNetworkStatuses function receives the defaultNetwork flag as an attribute, and thus, all the interfaces reported in teh CNI ADD for the default cluster network will be marked as default - something which breaks the multi-networking de-facto standard spec:

5.3.5 "default" This required key’s value (type boolean) shall indicate that this attachment is the result of the cluster-wide default network. Only one element in the Network Attachment Status Annotation list may have the "default" key set to true.

To comply with the standard, only of the interfaces must be defined as the default one.

k8snetworkplumbingwg / network-attachment-definition-client

When the result of the CNI ADD for the cluster default network features multiple interfaces, all are reported w/ `default: true` #69