As far as I know, there isn't a way to make the player able to evade/roll the same way the AI does.
I know there has been some Halo Custom Edition maps that have enabled it for the player (when playing as Elites) but that would've been done through scripting.
I was only able to perform an evade because it was an AI that I bump possessed. I had no control over whether I evade rolled, it was performed automatically by the AI. I could control where the ai moved and where I fired, but evading was still controlled by the AI.