chore: Update gson to 2.8.9 (#1335)

Signed-off-by: Sheng Chen <sheche@microsoft.com>

java-extension/com.microsoft.java.test.runner/pom.xml

@@ -14,7 +14,7 @@
     <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>
-      <version>2.8.5</version>
+      <version>2.8.9</version>
     </dependency>
     <dependency>
       <groupId>org.testng</groupId>