TBR: Upgrading gradle to 2.3

Change-Id: Ibb260544b9e7d1b07ae9813df080abed674ad3f4
diff --git a/java/gradle/wrapper/gradle-wrapper.properties b/java/gradle/wrapper/gradle-wrapper.properties
index d72ca1a..08e0fba 100644
--- a/java/gradle/wrapper/gradle-wrapper.properties
+++ b/java/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.3-all.zip