Is there an option to remove this notification message on phone call screen?
This is how you turn it off, uncheck show extra details 
This extra info is actually really important to have, in many phone calls, the problem is that the design is very bad. Only if Samsung designers, could follow the same design language throughout the OS.. Or apps even.. Like for instance, clicking on options or phone key pad, it has a nice frosted look, blending with the rest of the screen.. Why is this one different and distracting?! If they follow this very same design already in the phone app, it wouldn't look this bad. Is really hard for many of us to understand the logic of the design decisions that Samsung makes sometimes.. I just don't get why there's a lot of random disconnect ๐คฆ๐ผโโ๏ธ 
