Since the project members were previously discussing bundling FlorisBoard instead of the default AOSP keyboard (I believe this is no longer being considered, correct me if I am wrong), I want to make a recommendation about replacing the AOSP gallery app with this.
It is licensed permissively (Apache-2.0 license), is maintained, has a minimal UI and is written in Kotlin. However, it does not include a video editor but has a built-in photo editor.
(I am not related to this project in any way, just making a suggestion of a nice app I like using.)
Edit: Appears they are working on adding a video editor.