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)
(cherry picked from commit 5d72fdfcb2d8bc1415b3a603075048a231da18ca)
Change-Id: I7bcea58613340bf97a5038da40a3643971f99364

hadoop-project/pom.xml

@@ -129,7 +129,7 @@
     <okhttp.version>2.7.5</okhttp.version>
     <jdom.version>1.1</jdom.version>
     <grizzly.version>2.2.21</grizzly.version>
-    <gson.version>2.2.4</gson.version>
+    <gson.version>2.8.9</gson.version>
     <htrace3.version>3.1.0-incubating</htrace3.version>
     <htrace4.version>4.1.0-incubating</htrace4.version>
     <metrics.version>3.2.4</metrics.version>