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/cdm/core/test/test_base.cpp

@@ -374,6 +374,12 @@ void WvCdmTestBase::Provision() {
 }
 
 void WvCdmTestBase::EnsureProvisioned() {
+  // TODO: b/305093063 - Remove when Drm Reprovisioning server is implemented.
+  if (wvoec::global_features.provisioning_method ==
+      OEMCrypto_DrmReprovisioning) {
+    GTEST_SKIP()
+        << "Skipping until Drm Reprovisioning server support is implemented.";
+  }
   CdmSessionId session_id;
   std::unique_ptr<wvutil::FileSystem> file_system(CreateTestFileSystem());
   // OpenSession will check if a DRM certificate exists, while