Upgrade Netty to 4.1.68 (aws#2708)

Author: zoewangg

.changes/next-release/feature-AWSSDKforJavav2-3dc34f6.json

@@ -0,0 +1,6 @@
+{
+    "category": "AWS SDK for Java v2", 
+    "contributor": "", 
+    "type": "feature", 
+    "description": "Upgrade Netty to 4.1.68"
+}

pom.xml

@@ -100,8 +100,8 @@
         <commons.io.version>2.5</commons.io.version>
         <equalsverifier.version>3.5</equalsverifier.version>
         <!-- Update netty-open-ssl-version accordingly whenever we update netty version-->
-        <!-- https://github.com/netty/netty/blob/4.1/pom.xml#L384 -->
-        <netty.version>4.1.66.Final</netty.version>
+        <!-- https://github.com/netty/netty/blob/4.1/pom.xml search "tcnative.version" -->
+        <netty.version>4.1.68.Final</netty.version>
         <unitils.version>3.4.6</unitils.version>
         <xmlunit.version>1.3</xmlunit.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -126,7 +126,7 @@
         <jimfs.version>1.1</jimfs.version>
         <testng.version>7.1.0</testng.version> <!-- TCK Tests -->
         <commons-lang.verson>2.6</commons-lang.verson>
-        <netty-open-ssl-version>2.0.40.Final</netty-open-ssl-version>
+        <netty-open-ssl-version>2.0.42.Final</netty-open-ssl-version>
         <dynamodb-local.version>1.16.0</dynamodb-local.version>
         <sqllite.version>1.0.392</sqllite.version>