Remove Sub-Licenses and Sub-Sessions

(This is a merge of http://go/wvgerrit/66643)

The sub-license feature has been removed from the server and packager.
So that we do not have to continue maintaining the code that supports
this feature that never shipped, I am removing it from the CDM as well.

Bug: 113165466
Test: CE CDM Unit Tests
Test: Android Unit Tests
Change-Id: I5d25844b161e74aa19adf19a29c56e4881aa7304

libwvdrmengine/cdm/core/src/cdm_session.cpp

@@ -418,18 +418,6 @@ CdmResponseType CdmSession::GenerateKeyRequestInternal(
       return KEY_REQUEST_ERROR_1;
     }
 
-    std::vector<video_widevine::SubLicense> embedded_key_data =
-        init_data.ExtractSublicenseKeys();
-    for (size_t i = 0; i < embedded_key_data.size(); ++i) {
-      CdmResponseType sts = crypto_session_->AddSubSession(
-          embedded_key_data[i].sub_session_key_id(),
-          embedded_key_data[i].group_id());
-      if (NO_ERROR != sts) {
-        LOGE("CdmSession::GenerateKeyRequest: Unable to generate sub session");
-        return sts;
-      }
-    }
-
     app_parameters_ = app_parameters;
     CdmResponseType status = license_parser_->PrepareKeyRequest(
         init_data, license_type, app_parameters, &key_request->message,