Avast has added something to their software which Google Chrome tip whenever it informs you of an database update:

It seems to only be the same message at the moment, as I am only getting the

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How can I stop it from giving me this tip and only show me the virus definitions have been updated message?

Your virus definitions have been automatically updated

I have tried looking under Settings > Popups, however I cannot find an option to disable it there. I tried these settings that is in my answer

In the avast! settings interface there is an option to turn off recommendations and tips:

Settings > Community

Edit: It doesn't seem to work anymore, it worked for the next 2 database updates and now it is showing the tip again.