I made a contribution to an MPL 2.0-licensed project a while ago. I am not the maintainer of this project, I don't own it and I'm not affiliated to it in any way (apart from this specific benevolent contribution I made in my spare time). I did not sign a CLA, I just made the PR to GitHub and that PR was merged and released a few days later.
Now, I realize that the contribution I made to this MPL 2.0 project months ago could be useful to other projects that I may or may not own, and which are under different licenses (GPL 3.0, public domain, proprietary, Apache 2.0, …). Am I allowed to take the contribution I made to the MPL 2.0 project and redistribute it somewhere else into public domain without the maintainers agreement and without the MPL 2.0 license notice? Obviously, I would only redistribute the code from my contribution and not the modifications others may have made to my code since then. Am I still the legal "owner" of the code I wrote back then although it was published in an MPL 2.0 codebase first?