Add ICMP header length constant

Bug: 277376698
Test: m
Change-Id: I7edcf0f809bb9d5fa72e2c70110efabbaa349adf
diff --git a/staticlibs/framework/com/android/net/module/util/NetworkStackConstants.java b/staticlibs/framework/com/android/net/module/util/NetworkStackConstants.java
index aa2dd4c..96f6aac 100644
--- a/staticlibs/framework/com/android/net/module/util/NetworkStackConstants.java
+++ b/staticlibs/framework/com/android/net/module/util/NetworkStackConstants.java
@@ -135,7 +135,7 @@
      *     - https://tools.ietf.org/html/rfc792
      */
     public static final int ICMP_CHECKSUM_OFFSET = 2;
-
+    public static final int ICMP_HEADER_LEN = 8;
     /**
      * ICMPv6 constants.
      *