[Android] Fix managed install.

It was missing a comma, breaking gyp.
BUG=158821
TBR=cjhopman
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/13945019

git-svn-id: http://src.chromium.org/svn/trunk/src/build@193686 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

java_apk.gypi

@@ -332,7 +332,7 @@
             '<(final_apk_path)',
           ],
           'outputs': [
-            '<(apk_install_stamp)'
+            '<(apk_install_stamp)',
             # If a user switches the connected device, the APK may need to be
             # installed even if there have been no changes. To ensure that the
             # APK on the device is always up-to-date, this step should always