"The information we collect includes unique identifiers, browser type and settings, device type and settings, operating system, mobile network information including carrier name and phone number, and application version number. If you're using an Android device with Google apps, your device periodically contacts Google servers to provide information about your device and connection to our services. This information includes things like your device type and carrier name, crash reports, which apps you've installed."
Google collects a broad range of device data including installed apps, carrier information, phone number, sensor data, and unique identifiers, much of which goes beyond what is needed for core service functionality.