[package_info_plus] Sync example code with app-facing package

[HakkyuKim]

This PR partially syncs the example code of package_info_plus_tizen with that of package_info_plus package. This will be released together with the next notable change.

Context: #150 (comment)

[bwikbs]

I'm pretty hard to understand context 😄

[HakkyuKim]

Basically, the package_info_plus made a breaking change in 1.0.4 by adding a required parameter to the PackageInfo's public constructor:

Before:

PackageInfo({
  required this.appName,
  required this.packageName,
  required this.version,
  required this.buildNumber,
});

After:

PackageInfo({
  required this.appName,
  required this.packageName,
  required this.version,
  required this.buildNumber,
  required this.buildSignature,
});

The example code's pubspec.yml sets package_info_plus dependency to ^1.0.1 which allows the tool to get the highest minor.patch version available in pub dev. In this case, however, the semantic versioning was not honored therefore the example app failed to build itself. The maintainers will release a new patch fixing this problem but I'm just taking the opportunity to update the code.

[bwikbs]

@HakkyuKim I didn't mean that.. Thanks for the detailed explaination! 💯

[HakkyuKim]

@bwikbs
Oh okay, my bad. Thanks for a quick review!