FIX: Android device doesn't show up in Google Play Store device list

Somewhere along the way while flashing updates to the AOKP ROM to my Nexus 7 (2012), the Nexus stopped showing up in the device list on the web version of the Google Play store. But the Play store functioned properly on the Nexus: I could install new apps, got updates for existing apps, etc.

Since I saw the problem on the Play website and Play worked great on the Nexus itself, I thought the problem was "Google-wide". I cleared cache and data for Google Play services on the Nexus. No luck. I went to the Google dashboard and deleted the duplicate entries for my N7 (duplicates are a result of flashing ROMs to my device). Didn't work.

It turns out my assumption that the problem was Google-wide was wrong. The fix turned out to be easy.

This fixed the problem for me:

• Clear Play Store data. Go to Settings->Apps and scroll down until you see Google Play Store and tap it. Tap Clear Cache and then Clear Data. 
• Reboot device
• Wait a few minutes
• Check the Play store website
• Do a happy dance

After doing this, my Nexus 7 shows up again.