fix: set applicationId

[seamlink-aalves]

Platforms affected

Motivation and Context

Description

Fix camera launcher #744

Testing

I invoked the camera plugin successfully

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[breautek]

I think this is a good overall change.

org.apache.cordova.BuildHelper is a utility class for accessing the app's BuildConfig class, which is a class that is generated by gradle builds. It won't exist if the project happens.

Additionally the BuildHelper class makes use of reflections, which can make debugging difficult and stacktraces mostly useless (since it will hard what you're trying to invoke).

Context.getPackageName is a SDK level 1 API which returns the same information as the OS knows it (powered by the AndroidManifest). It should be guaranteed to be accurate and available.

While the BuildHelper class may have uses, if we can get the same information from concrete android APIs, I think that should be the more preferable approach 👍