Really ? My fiancé is from Jakarta Utara and everyone rolls their R’s like that. Better example to prove this is every time I’ve been in Jakarta I’ve spoken to locals and when I don’t roll my r’s they always have a confused look on their face as if the word was completely different that I said, but when I roll the R sound they go “ohhh mengerti”.
Another fact you have to remember is all the Malay based lanagues have borrowed a lot from Arabic (due to history) and that’s the reason why the R’s in the Malay lanagues are trilled.
some context to that last part I’m from western Scotland (Glasgow) and our accent means we don’t roll our “r’s”, it’s more light sounding when we pronounce the “r” sound, it Almost like we are saying “ahh” and not “Arrr”