We are still missing the real LDT implementation, so the code is linked with a
placeholder code that doesn't do the actual encryption.
PiperOrigin-RevId: 484596294
Refactoring change.
Merge CertificateManager and CredentialManager into a single interface.
Hide AdvertisementFactory in implementation/. The client app will not be using
that class directly.
Clean up build targets.
PiperOrigin-RevId: 466748133