I'm considering turning a static notification bar icon in my application to an animated one, since it seems that it would make identification of the app state a bit easier for users.
I've checked it and figured out that animated icons (animation-list Drawables)indeed work in the notification bar.
But I can't recall I've ever seen animated icons in the notification bar except system ones (e.g. battery when charging). Also, I can't find guidelines from Google on this matter.
Are animated notification bar icons acceptable\recommended according to Google's requirements\guidelines?
I think it is not recommended to use by Google but acceptable.
Google: We make Android guidelines only to not follow them and force everybody else to do the same.
I did not find any official Google guidelines for animeted Notification icons but there is a lot of usefull information
https://material.io/guidelines/patterns/notifications.html#notifications-behavior