Display Drive detection warning only for multiple drives (#7589)

* indexer drive detection helper code to not show the warning for a single drive

* removed interface from the namespace due to stylecop

* removed interfac which no longer exists

* filter out only fixed drives in the system and ignore the removable drives

* changed text to not all files are indexed, from not all drives are idnexed

* add additional info in the comment

src/modules/launcher/Plugins/Microsoft.Plugin.Indexer/DriveDetection/DriveInfoWrapper.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.IO;
+using System.Linq;
+
+namespace Microsoft.Plugin.Indexer.DriveDetection
+{
+    public class DriveInfoWrapper : IDriveInfoWrapper
+    {
+        private static readonly int DriveCount = GetDriveInfo();
+
+        private static int GetDriveInfo()
+        {
+            // To ignore removable type drives, CD ROMS, no root partitions which may not be formatted and only return the fixed drives in the system.
+            return DriveInfo.GetDrives().Where(d => d.DriveType == DriveType.Fixed).Count();
+        }
+
+        public int GetDriveCount() => DriveCount;
+    }
+}