.ci/legacy_project/README.md

This directory contains a partial snapshot of an old Flutter project; it is
intended to replace the corresponding parts of a newly Flutter-created project
to allow testing plugin builds with a legacy project.

It was originally created with Flutter 2.0.6. In general the guidelines are:
- Pieces here should be largely self-contained rather than portions of
  major project components; for instance, it currently contains the entire
  `android/` directory from a legacy project, rather than a subset of it
  which would be combined with a subset of a new project's `android/`
  directory. This is to avoid random breakage in the future due to
  conflicts between those subsets. For instance, we could probably get
  away with not including android/app/src/main/res for a while, and
  instead layer in the versions from a new project, but then someday
  if the resources were renamed, there would be dangling references to
  the old resources in files that are included here.
- Updates over time should be minimal. We don't expect that an unchanged
  project will keep working forever, but this directory should simulate
  a developer who has done the bare minimum to keep their project working
  as they have updated Flutter.
- Updates should be logged below.

The reason for the hybrid model, rather than checking in a full legacy
project, is to minimize unnecessary maintenance work. E.g., there's no
need to manually keep Dart code updated for Flutter changes just to
test legacy native Android build behaviors.

## Manual changes to files

The following are the changes relative to running:

```bash
flutter create -a java all_packages
```

and then deleting everything but `android/` from it:

- Added license boilerplate.
- Replaced `jcenter` in build.gradle with `mavenCentral`, due to the
  jcenter.bintray.com shutdown.