Update cpe for vulnerability scanners

Bug: http://b/201572953
Change-Id: I9505edd78cd6da0cedff2fe29751ba6d3a3d625d
diff --git a/METADATA b/METADATA
index 4088c2c..51bcfd9 100644
--- a/METADATA
+++ b/METADATA
@@ -16,4 +16,7 @@
     month: 8
     day: 20
   }
+  security {
+      tag: "NVD-CPE2.3:cpe:/a:tcpdump:tcpdump:4.9.3"
+  }
 }