This doesn't refer to a coda (which is never called a "cola" in my experience). Nor is it using "cola" in the sense of definition 15, which I admit is new to me and which I suppose you would call a pause or (more formally) a fermata. It explicitly refers to the introduction of the song, which consists of "tres notas graves ascendentes con una pequeña cola", played four times before the voice comes in. The three rising notes (B, C#, E) are played in the lower strings, followed by drum beats the first time and by a higher six-note figure from the violins the other three times (slightly different each time). It's more or less like this:

DA - DA - DA - (da-dada-dada-da)
DA - DA - DA - (da-da-dada-dada-da).

DA DA DA are the tres notas graves ascendentes and the bit in lower case in parentheses is the cola. It just means a "tail" to the phrase, but I don't think you would call it a tail in English. I don't think there's a technical term for it. I would just call it a little figure at the end (of the phrase), or you could say "three low rising notes followed by a little figure", for example. Something like that.