Add custom ice stdnet implementation (#754)

On Android, because of the hard SELinux policies can not list the
interfaces of the ICE package. Without it can not generate a host type
candidate. In this pull request, the list of interfaces comes via the Java
interface.

client/internal/peer/stdnet_android.go

@@ -0,0 +1,7 @@
+package peer
+
+import "github.com/netbirdio/netbird/client/internal/stdnet"
+
+func (conn *Conn) newStdNet() (*stdnet.Net, error) {
+	return stdnet.NewNet(conn.iFaceDiscover)
+}