Fact check: Google did not automatically sign up Android users for COVID-19 tracing app
USA Today article.
Apple and Google did recently add exposure notifications to devices under Settings, but the contact tracing technology works only if one has opted in and enabled the notifications.
https://eu.usatoday.com/story/news/factcheck/2020/06/14/fact-check-android-users-must-opt-into-covid-19-tracing-technology/5341250002/