what does it mean by built in wallet? it could mean that it's a wallet app pre-installed but you can always install it from playstore. Its good to hear that these companies are stepping forwards in adopting blockchain but at the same time hardware wallet is the best way to go and I am not sure built in smartphone wallet would be a good place to store your bitcoin
The wallet that has already provided by samsung is only for the samsung phone and it's not available on the playstore and if you didn't believe it and you can check it.
Im also a samsung user that my handheld has already installed the samsung crypto wallet too.