Remove unused variable in MtuUtils

Test: atest FrameworksNetTests
Change-Id: If2abfec1e5755b3f8cc17fb307ec3e1633bb3e18
diff --git a/services/core/java/com/android/server/vcn/util/MtuUtils.java b/services/core/java/com/android/server/vcn/util/MtuUtils.java
index 49c1a02..5d40cca 100644
--- a/services/core/java/com/android/server/vcn/util/MtuUtils.java
+++ b/services/core/java/com/android/server/vcn/util/MtuUtils.java
@@ -113,7 +113,6 @@
             return IPV6_MIN_MTU;
         }
 
-        boolean hasUnknownAlgorithm = false;
         int maxAuthOverhead = 0;
         int maxCryptOverhead = 0;
         int maxAuthCryptOverhead = 0;