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/include/license.h

@@ -108,7 +108,6 @@ class CdmLicense {
 
   CdmResponseType HandleNewEntitledKeys(
       const std::vector<WidevinePsshData_EntitledKey>& wrapped_keys);
-  CdmResponseType HandleSubLicense(const InitializationData& init_data);
 
   template <typename T>
   bool SetTypeAndId(CdmLicenseType license_type, const std::string& request_id,
@@ -147,11 +146,6 @@ class CdmLicense {
   // entitelement keys. It is also used in updating the key status info.
   std::vector<WidevinePsshData_EntitledKey> wrapped_keys_;
 
-  // For sublicense key embedding. This key array will be initialized with any
-  // sub session keys we may have received in a license response. These keys
-  // may be used to support key rotation.
-  std::vector<CryptoKey> entitlement_key_array_;
-
   CdmLicenseKeyType license_key_type_;
   RepeatedPtrField<License_KeyContainer> entitlement_keys_;
 #if defined(UNIT_TEST)