Any passwords that were saved by Chrome (not Avast) should still be there, even if you uninstall Avast. You can check in Chrome to see:

https://support.google.com/chrome/answer/95606?co=GENIE.Platform%3DDesktop&hl=en

As a precaution, you can export the passwords from Avast’s Settings before uninstalling Avast:

https://help.avast.com/en/av_free/17/page_passwords_settings.html