Add paths to windows metadataFiles

When creating a new empty base layer on Windows, hcsshim creates a set
of empty registry hives in C:\Windows\System32\config. These files are
needed in order for the new layer to be considered valid.

Add these locations to the metadataFiles, which excludes them when
comparing the diffs of two layers.

Signed-off-by: Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>

fs/fstest/compare_windows.go

@@ -19,6 +19,14 @@ package fstest
 // TODO: Any more metadata files generated by Windows layers?
 // TODO: Also skip Recycle Bin contents in Windows layers which is used to store deleted files in some cases
 var metadataFiles = map[string]bool{
-	"\\System Volume Information": true,
-	"\\WcSandboxState":            true,
+	"\\System Volume Information":           true,
+	"\\WcSandboxState":                      true,
+	"\\Windows":                             true,
+	"\\Windows\\System32":                   true,
+	"\\Windows\\System32\\config":           true,
+	"\\Windows\\System32\\config\\DEFAULT":  true,
+	"\\Windows\\System32\\config\\SAM":      true,
+	"\\Windows\\System32\\config\\SECURITY": true,
+	"\\Windows\\System32\\config\\SOFTWARE": true,
+	"\\Windows\\System32\\config\\SYSTEM":   true,
 }