Inventory of Firebase Applications Privacy and Data Collected

Question

According to Google docs for indexing Firebase applications:

https://firebase.google.com/docs/app-indexing/

"Privacy note: The index of personal content exists only on the user's device. None of the user's personal files are uploaded to Google’s servers, and it remains on the device only when the application is installed. However, aggregated statistics on the use of application indexing applications and other information system status can be uploaded to Google’s servers. To view or delete any actions in the public content registered in your application, the gender Users can go to "(see screenshot below)

My question here is about collected aggregated statistics from Android application clients? Is the data collected anonymous or contains information related to the user? I ask this question since the documents do not provide any information about indexing Firebase applications that collect data.

thanks