Metered wi-fi connection on Android tablet? I have a non-rooted Nexus 7 (2013), and connect to the internet via a Mi-Fi hotspot.

I have a low data cap, so I need to track usage closely. I'd like to be able to mark my connection as metered, but since this is a tablet, those options don't exist in Data Usage.

Is there any app or alternative method to enable that functionality?
At least on my Nexus 10:

Settings → Data Usage → ⋮ menu → Network Restrictions

brings up a screen where you can set whether each WiFi network is metered or not.