device: ratchet up max segment size on android

GRO requires big allocations to be efficient. This isn't great, as there
might be Android memory usage issues. So we should revisit this commit.
But at least it gets things working again.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

device/queueconstants_android.go

@@ -14,6 +14,6 @@ const (
 	QueueOutboundSize          = 1024
 	QueueInboundSize           = 1024
 	QueueHandshakeSize         = 1024
-	MaxSegmentSize             = 2200
+	MaxSegmentSize             = (1 << 16) - 1 // largest possible UDP datagram
 	PreallocatedBuffersPerPool = 4096
 )