I don't see you shorten the 1st element in the array. I see you shift all the elements in the array and update the latest.
Beside using System.arraycopy, I can't see how you can get faster.
You can use a linked array, perhaps.
Or you can maintain an index on the latest updated entry. On each new entry, increment this index, modulo the size of the array. And when using the array, start iterating on the index + 1 modulo array size (the oldest entry). Thus, no data copy, just seeing the array as a loop (like a circular ribbon) with an entry point.