fix: Issues when using UTP 2.0.0-exp.6 (#2224)

* fix: Bind to server endpoint when using Relay

* Fix NativeArray conversion

* Simplify creation of DataStreamReader

Author: simon-lemay-unity

com.unity.netcode.gameobjects/Runtime/Transports/UTP/BatchedSendQueue.cs

@@ -208,19 +208,12 @@ public int FillWriterWithMessages(ref DataStreamWriter writer)
 
             unsafe
             {
-                var dataPtr = (byte*)m_Data.GetUnsafePtr() + HeadIndex;
-
-#if UTP_TRANSPORT_2_0_ABOVE
-                var slice = NativeArray.ConvertExistingDataToNativeArray<byte>(dataPtr, Length, Allocator.None);
-                var reader = new DataStreamReader(slice);
-#else
-                var reader = new DataStreamReader(dataPtr, Length);
-#endif
+                var reader = new DataStreamReader(m_Data.AsArray());
 
                 var writerAvailable = writer.Capacity;
-                var readerOffset = 0;
+                var readerOffset = HeadIndex;
 
-                while (readerOffset < Length)
+                while (readerOffset < TailIndex)
                 {
                     reader.SeekSet(readerOffset);
                     var messageLength = reader.ReadInt();

com.unity.netcode.gameobjects/Runtime/Transports/UTP/UnityTransport.cs

@@ -482,6 +482,7 @@ private bool ClientBindAndConnect()
                 }
 
                 m_NetworkSettings.WithRelayParameters(ref m_RelayServerData, m_HeartbeatTimeoutMS);
+                serverEndpoint = m_RelayServerData.Endpoint;
             }
             else
             {