feat: snapshot, using unreliable packets, now that the underlying foundation supports it. Only merge after #1062 (#1064)

Author: jeffreyrainy

com.unity.netcode.gameobjects/Runtime/Transports/NetworkTransport.cs

@@ -104,8 +104,7 @@ public TransportChannel[] NETCODE_CHANNELS
             // todo: Currently, fragmentation support needed to deal with oversize packets encounterable with current pre-snapshot code".
             // todo: once we have snapshotting able to deal with missing frame, this should be unreliable
             new TransportChannel(NetworkChannel.NetworkVariable, NetworkDelivery.ReliableSequenced),
-            new TransportChannel(NetworkChannel.SnapshotExchange, NetworkDelivery.ReliableSequenced), // todo: temporary until we separate snapshots in chunks
-
+            new TransportChannel(NetworkChannel.SnapshotExchange, NetworkDelivery.Unreliable),
             new TransportChannel(NetworkChannel.Fragmented, NetworkDelivery.ReliableFragmentedSequenced),
 
         };