Samaung S7 locked out
Booting into recovery and doing a factory reset is pretty much your only option.
To get into recovery:
Press and hold “Volume UP + Power + Home” button together and as soon as you see Galaxy S7 Boot logo, release all three buttons.
When you see an exclamation mark on screen, press and hold Power button and hit the Volume Up button once.
Then select factory reset and go thru all the setup again..