Cdm to expose GetDeviceInformation() and GetDeviceSignedCsrPayload()

[ Merge of https://widevine-internal-review.googlesource.com/c/cdm/+/178890/ ]

GetDeviceInformation() and GetDeviceSignedCsrPayload() are added to
cdm_engine and crypto_session, so that they can be queried by DRM
plugin. This is to allow the wv drm HAL to be able to extract BCC and
CSR payload to build CSR for prov 4 device registration, such that we
don't need a separate RKP HAL to do this job.

Changes to the DRM plugin to use the exposed methods will be in the
coming CL.

Bug: 286556950
Test: request_license_test
Change-Id: I5f7aed8b3471ea477b79d08b95e1d217dc39070b

libwvdrmengine/cdm/core/include/cdm_engine.h

@@ -180,6 +180,11 @@ class CdmEngine {
   virtual CdmResponseType QueryOemCryptoSessionId(
       const CdmSessionId& session_id, CdmQueryMap* query_response);
 
+  // Query Signed CSR payload for Prov 4 device
+  virtual CdmResponseType QueryDeviceSignedCsrPayload(
+      const std::string& challenge, const std::string& device_info,
+      std::string* query_response);
+
   // Generate and return a valid provisioning request.
   virtual CdmResponseType GetProvisioningRequest(
       CdmCertificateType cert_type, const std::string& cert_authority,