This PR contributes to https://github.com/flutter/flutter/issues/130459
### Description
- Corrects the name for `examples/api/test/widgets/shortcuts/logical_key_set.0_test.dart` test file
- Update tests for `examples/api/lib/widgets/shortcuts/logical_key_set.0.dart`
This PR contributes to https://github.com/flutter/flutter/issues/130459
### Description
- Corrects the name for `examples/api/test/widgets/shortcuts/callback_shortcuts.0_test.dart` test file
- Update tests for `examples/api/lib/widgets/shortcuts/callback_shortcuts.0.dart`
This PR contributes to https://github.com/flutter/flutter/issues/130459
### Description
- Adds tests for `examples/api/lib/widgets/shortcuts/shortcuts.0.dart`
- Adds tests for `examples/api/lib/widgets/shortcuts/shortcuts.1.dart`
This PR contributes to https://github.com/flutter/flutter/issues/130459
### Description
- Fixes name of the `examples/api/lib/widgets/shortcuts/single_activator.single_activator.0.dart`
- Adds tests for `examples/api/lib/widgets/shortcuts/single_activator.0.dart`
This PR contributes to https://github.com/flutter/flutter/issues/130459
### Description
- Adds `examples/api/lib/widgets/shortcuts/character_activator.0.dart` test
- Fixes the description of the `examples/api/lib/widgets/shortcuts/character_activator.0.dart` example
