Add IPv6 overlay address support to client interface and engine

client/android/peer_notifier.go

@@ -5,6 +5,7 @@ package android
 // PeerInfo describe information about the peers. It designed for the UI usage
 type PeerInfo struct {
 	IP         string
+	IPv6       string
 	FQDN       string
 	ConnStatus string // Todo replace to enum
 	Routes     PeerRoutes