I can confirm that the Gallery Recycle Bin is not available on the Galaxy S7. If you head to Apps > Google (folder) > Photos, can you see an archive of your images here? Alternatively, follow the link below via an internet browser and sign in using your Google account details.
If you have taken the backup either on Google account or local backup then, it may be possible to recover photo by using the backup. Just need to check your backup data if there is available your pictures then, you can simply restore it. Otherwise, if you doesn't find your deleted pictures then, you may also try another best Android data recovery solution to retrieve photos. I hope you will get back your pictures. Good Luck!