HADOOP-13464. Upgrade Gson dependency to version 2.8.9 (#2524)

Change-Id: Ifd3fb9ec6ebfc8874bb799bc198219511fe55a2f

Update pom.xml

Update pom.xml

(cherry picked from commit 795054882af72a9d5d4f4e96f775e96473d75c23)

hadoop-project/pom.xml

@@ -139,7 +139,7 @@
     <jdom.version>1.1</jdom.version>
     <jna.version>5.2.0</jna.version>
     <grizzly.version>2.2.21</grizzly.version>
-    <gson.version>2.2.4</gson.version>
+    <gson.version>2.8.9</gson.version>
     <metrics.version>3.2.4</metrics.version>
     <netty3.version>3.10.6.Final</netty3.version>
     <netty4.version>4.1.68.Final</netty4.version>