Earlier quoted context omitted.
Interesting. I dropped Android a year or so back but can't remember bumping into an app doing it like that. Definitely encountered a few "are you sure?" style dialogues though.
The UI element typically used for this is the "Snackbar", so if you search for "Android Snackbar", you should find some examples. But yeah, I definitely also see a lot more confirm-dialogs still. Seems to be a classic case of such a UI pattern being great and hyper modern and marketable in 99% of cases. But if in 1% of cases, the user accidentally deletes a file that they didn't want to delete, then you lose that use…
Perfect example of a UX pattern that's simply asking for trouble, or being clever rather than helpful. :)
You can undo if you notice quickly enough, if your dog, child, doorbell or 1,001 other things didn't distract you at the wrong moment and if you didn't get an incoming call in the temporary undo window. No, we won't tell you how long you can undo for, even though times can vary. Don't be old (or even middle-aged needing reading glasses), or slow.
Seems very much against long known recommendations from Nielsen et al for consistency of expectation etc.
A quick skim through search seems to indicate it came with Material Design. I suspect had it generally caught on it my switch to iOS would have come even sooner. :D