Resolves#2519
Part of the larger effort to bring the samples/repo into a stable and
maintainable condition that _also_ remains useful. See: #2409
## Pre-launch Checklist
- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I have added sample code updates to the [changelog].
- [x] I updated/added relevant documentation (doc comments with `///`).
Eric Windmill