Update icon

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit 9f8c395):

https://flutterkakgi-2023-conf-app-dev--pr83-update-icons-42mc9upn.web.app

_{(expires Sun, 27 Aug 2023 05:48:40 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

_{Sign: 1cac8c9fbcf8c2f43fea34942176b864ab92a752}