Updated Xamarin.Messaging version (#13145)

* Updated Xamarin.Messaging version

* Adapt BuildAgent to new Messaging changes

msbuild/Directory.Build.props

@@ -1,6 +1,6 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 	<PropertyGroup>
-		<MessagingVersion>1.4.4</MessagingVersion>
+		<MessagingVersion>1.4.7</MessagingVersion>
 		<HotRestartVersion>1.0.82</HotRestartVersion>
 	</PropertyGroup>
 </Project>

msbuild/Messaging/Xamarin.Messaging.Build/BuildAgent.cs

@@ -6,13 +6,17 @@ using Xamarin.Messaging.Client;
 
 namespace Xamarin.Messaging.Build {
 	public class BuildAgent : Agent {
+		readonly AgentInfo buildAgentInfo;
+
 		public BuildAgent (ITopicGenerator topicGenerator, string version = null, string versionInfo = null) : base (topicGenerator)
 		{
+			buildAgentInfo = new BuildAgentInfo ();
+
 			Version = string.IsNullOrEmpty (version) ? GetVersion () : version;
 			VersionInfo = string.IsNullOrEmpty (versionInfo) ? GetInformationalVersion () : versionInfo;
 		}
 
-		public override string Name => BuildAgentInfo.Instance.Name;
+		public override string Name => buildAgentInfo.Name;
 
 		public override string Version { get; }