- Part of #653.
- No need for `defaultCommand` since ContainerService startup will write
a new launchd plist with the `start` subcommand included.
## Type of Change
- [ ] Bug fix
- [ ] New feature
- [ ] Breaking change
- [ ] Documentation update
## Motivation and Context
Allows us to add commands to support post-installation, migration, etc.
## Testing
- [x] Tested locally
- [ ] Added/updated tests
- [ ] Added/updated docs