Move PullNupkgFilesFromBlob into FinalizeBuild.

Also, update dotnet/versions for the DotNetHost and NetCore.App packages.

Fix #3031

build_projects/shared-build-targets-utils/Utils/GitUtils.cs

@@ -0,0 +1,32 @@
+using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
+
+namespace Microsoft.DotNet.Cli.Build
+{
+    public static class GitUtils
+    {
+        public static int GetCommitCount()
+        {
+            return int.Parse(ExecuteGitCommand("rev-list", "--count", "HEAD"));
+        }
+
+        public static string GetCommitHash()
+        {
+            return ExecuteGitCommand("rev-parse", "HEAD");
+        }
+
+        public static string GetBranchName()
+        {
+            return ExecuteGitCommand("rev-parse", "--abbrev-ref", "HEAD");
+        }
+
+        private static string ExecuteGitCommand(params string[] args)
+        {
+            var gitResult = Cmd("git", args)
+                .CaptureStdOut()
+                .Execute();
+            gitResult.EnsureSuccessful();
+
+            return gitResult.StdOut.Trim();
+        }
+    }
+}