Enable app stats on '-dev' instance.
Enable app stats on '-dev' instance.

This will also enable them on local dev server as well since default app name
in app.yaml is 'isolateserver-dev'.

R=maruel@chromium.org

Review URL: https://codereview.appspot.com/13457054

luci/luci-py,pombreda/swarming,madecoste/swarming,madecoste/swarming,madecoste/swarming,luci/luci-py,luci/luci-py,luci/luci-py,pombreda/swarming,madecoste/swarming,pombreda/swarming,pombreda/swarming