mdatagen: using the wrong package name for a generateFile call

[braydonk]

Describe the bug
In #11232 I missed a spot where "metadata" is still being passed instead of the correct package name. This would cause a faulty generation when using the generated_package_name feature.

opentelemetry-collector/cmd/mdatagen/internal/command.go

Lines 83 to 86 in 388bae7

	if err = generateFile(filepath.Join(tmplDir, "status.go.tmpl"),
	filepath.Join(codeDir, "generated_status.go"), md, "metadata"); err != nil {
	return err
	}

Steps to reproduce
Off of 388bae7 (this is not in a released version of mdatagen), generate a package with a custom name. generated_status.go will have the wrong package name (metadata instead of the intended generated_package_name).

Additional context
As previously mentioned, this bug is not present in a released version of mdatagen yet.