Small edits to String.ToCharArray code snippet (dotnet#4170)

Author: carlossanlop

samples/snippets/csharp/VS_Snippets_CLR_System/system.string.tochararray/cs/ToCharArray1.cs

@@ -5,12 +5,14 @@ public class Example
 {
    public static void Main()
    {
-      String s = "AaBbCcDd";
-      var chars = s.ToCharArray();
+      string s = "AaBbCcDd";
+      char[] chars = s.ToCharArray();
       Console.WriteLine("Original string: {0}", s);
       Console.WriteLine("Character array:");
       for (int ctr = 0; ctr < chars.Length; ctr++)
+      {
          Console.WriteLine("   {0}: {1}", ctr, chars[ctr]);
+      }
    }
 }