Google has just posted the factory image of Android 5.0.2 Lollipop for the WiFi version of the 2012 Nexus 7. This follows the rollout of the Android 5.0.1 on many Nexus devices recently. With the factory image up, an OTA update can't be too far away, and we'll keep you posted on AndroidCentral if we see Android 5.0.2 on other Nexus smartphones and tablets.
The build for Android 5.0.2 is LRX22G. In addition to publishing the Android 5.0.2 factory image for the device, Google has also opted to pull the Android 5.0.1 image for the Nexus 7.