Document the declarative schema an OEM config APK can ship as
res/xml/oem_wizard.xml to contribute pages to the PawletOS setup wizard.
Documentation only; the default config APK ships no live oem_wizard.xml.
Without package="app.pawlet.config" in the manifest, AAPT2 builds the
APK with an empty package name, so createPackageContext("app.pawlet.config")
in ConfigProvisioner always throws NameNotFoundException.