Unknown Android notification message. Updating Data This morning my Project Fi Nexus 6P with Android 6.0.1 had an animated icon in the notification list with a progress bar and the text "Updating Data".  

Using the search features I didn't find anything that explained what it was.

Here's a screenshot:


Screenshot (click image to enlarge)
Zooming in to the icon helped identify the app as a Yellowstone guide app.

https://goo.gl/photos/H55YTqfJabp8uiB17