annex
Reads an Annex C request out of a platform-neutral Digital Credentials request.
Platforms that hand the wallet the whole request up front - Android Credential Manager - deliver the raw deviceRequest/encryptionInfo pair inside MobileWalletDigitalCredentialRequest.dataJson. That envelope shape is Annex C's, so it is decoded here rather than in each platform adapter. Apple's provider extension has no such envelope and constructs MobileWalletAnnexCRequest from its parsed request instead.