in my sister opinion
as she learnt Mandarin
she realised that...
during last time
the malays saw the dog
wandering in the village
and making noise
then the chinese came and shout,
" ANJING!!!! " (which mean "shut up!!" pronounce the same as "anjing" in malay")
which she think that by mistaken that the malays over hear it
then,there's goes the name came up.
*in mandarin,dog are called as "gong"