Update spot bugs to 3.1.9

Author: varunnvs92

.changes/next-release/feature-AWSSDKforJavav2-d146eed.json

@@ -0,0 +1,5 @@
+{
+    "category": "AWS SDK for Java v2", 
+    "type": "feature", 
+    "description": "Update spot bugs version to 3.1.9"
+}

pom.xml

@@ -94,7 +94,7 @@
         <unitils.version>3.3</unitils.version>
         <xmlunit.version>1.3</xmlunit.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <spotbugs.version>3.1.3.1</spotbugs.version>
+        <spotbugs.version>3.1.9</spotbugs.version>
         <netty-reactive-streams-http.version>2.0.0</netty-reactive-streams-http.version>
         <freemarker.version>2.3.24-incubating</freemarker.version>
         <javapoet.verion>1.11.1</javapoet.verion>