Add DRM reprovisioning request generation

[ Merge of http://go/wvgerrit/192010 ]

Updates the CDM to add support for DRM reprovisioning request creation.
- Load the baked-in certificate for use as the client token.
- Add functions to build and sign a drm reprovisioning request.
- Update the Rikers L3 OEMCrypto implementation to support signing
  provisioning requests and getting embedded certificate.
- Update client id token to handle DRM reprovisioning.
- Add OEMCrypto function to load the baked-in device certificate in
  Rikers CDMs and stubs for non-Rikers CDMs.
- Add dynamic adapter support for getting embedded device certificate
  only on L3.

Bug: 305093063
Test: WVTS
Change-Id: I9a0ecf95e27213b046f03baa0781fb164179323b

libwvdrmengine/oemcrypto/include/level3.h

@@ -125,6 +125,7 @@
 #define Level3_GetUsageEntryInfo           _lcc148
 #define Level3_GetBCCType                  _lcc149
 #define Level3_LoadRelease                 _lcc150
+#define Level3_GetEmbeddedDrmCertificate   _lcc151
 #else
 #define Level3_Initialize                  _oecc01
 #define Level3_Terminate                   _oecc02
@@ -233,6 +234,8 @@
 #define Level3_GetUsageEntryInfo           _oecc148
 #define Level3_GetBCCType                  _oecc149
 #define Level3_LoadRelease                 _oecc150
+// Internal-only.
+#define Level3_GetEmbeddedDrmCertificate   _oecc151
 #endif
 
 #define Level3_GetInitializationState     _oecl3o01
@@ -527,6 +530,8 @@ OEMCryptoResult Level3_LoadProvisioningCast(
     size_t signature_length, uint8_t* wrapped_private_key,
     size_t* wrapped_private_key_length);
 OEMCryptoResult Level3_GetBCCType(OEMCrypto_BCCType* bcc_type);
+OEMCryptoResult Level3_GetEmbeddedDrmCertificate(uint8_t* public_cert,
+                                                 size_t* public_cert_length);
 
 // The following are specific to Google's Level 3 implementation and are not
 // required.