Sadly I think that has become all part of the game...much as I like you, hate it.
It is not confined to one team or nationality, it has almost become the norm.
About the first time I really recall the diving/histrionics (or should that be 'istryonics?) was with Klinsmann. We then went a few years before it was Drogba (see...I blame Chelsea again!) and since then it has slowly crept in to being something that according to some pundits "is all part of the game".
Perhaps the most regular user of that phrase is Cundy on Talksport who views it as something players should do.
Yes Salah went down far too easily, but then there was some contact. As said all sides do it to some extent. The Soucek/Mitrovic one was a prime example, Salah against West Ham and Wellbeck against us beign others where there may have been the faintest of contacts (if at all) and they have gone down.
So is that gamesmanship when they respond to the contact or simply cheating? Oh for simpler times!!!
Whilst there may be times when it is a close call, you then get the complete wankers like Neymar and Rivaldo where you just have to shake your head and laugh at them.