Adds native-image-argfile plan entry to detection

[pivotal-david-osullivan]

Summary

This allows an upstream buildpack to provide native-image-argfile to trigger this buildpack to provide native-image-application and participate, without the need to set BP_NATIVE_IMAGE

Use Cases

Apps can provide a native-image argument file, indicating that a native build should automatically be triggered.

Checklist

• [ ] I have viewed, signed, and submitted the Contributor License Agreement.
• [ ] I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• [ ] I have added an integration test, if necessary.
• [ ] I have reviewed the styleguide for guidance on my code quality.
• [ ] I'm happy with the commit history on this PR (I have rebased/squashed as needed).

[dmikusa]

I tested this together with the boot change, so testing notes over on spring-boot: https://github.com/paketo-buildpacks/spring-boot/pull/279#issuecomment-1324475124

This PR looks good to me.