I don't want to set up Google photos to back up to the cloud for privacy reasons.
Recently I noticed that with the default Android camera app, and the default Google Photos app, the "Trash" is only used if you have the app set up to sync with your cloud service.
This means that any photo that's deleted from the camera roll—for example, by swiping from the camera to view the photos just taken, and then swiping down—is immediately unrecoverable. (There is an "undo" button briefly visible, and that's all.)
By contrast, in iOS (which my family members are more used to), any photo that you delete will go to the "Trash" where it will only be actually removed after 30 days, giving plenty of time to recover from any accidents or mistakes. (And in iOS, this feature doesn't require iCloud use at all.)
How can I set up my Android devices to mimic this functionality, so that photos deleted from the camera roll, or from the photos app, are still preserved for an additional 30 days unless special action is taken?
(I'm running a Nexus 7 with Android 6.0.1, but we have a couple other Android devices in the house that I would probably apply the answers to if I can.)