What are these google host entries that keep showing up automatically in my etc/hosts file?
216.239.32.20 seems to be a legit Google Inc. IP-address - so nothing to worry about in the first instance: Please check herdprotect.com.

The behavior is probably related to Kaspersky Security. Check this thread at discussions.apple.com.

To prevent the flooding of your hosts file uninstall Kaspersky Security. Then clean it up by editing it with sudo nano /etc/hosts.