Update build number (#12793)

src/AssemblySharedInfoGenerator/AssemblySharedInfo.tt

@@ -69,7 +69,7 @@ using System.Runtime.InteropServices;
 <#+
 int MajorVersion = 2;
 int MinorVersion = 6;
-int BuildNumber = 1;
+int BuildNumber = 2;
 // The datetime baseline we choose using this algorithm will affect build number and all nuget packages uploaded
 // Please only change when major or minor version got incremented
 int RevisionNumber = ((int)(DateTime.UtcNow - new DateTime(2018,1,1)).TotalDays)*10+((int)DateTime.UtcNow.Hour)/3;