Create unique cdm engines per WVDrmPlugin instance

This change creates a unique id in the cdm identifier in order to force
a one-to-one mapping between WVDrmPlugin instances and CDM Engines. This
change simplifies some assumptions. This includes ensuring that the
metrics for a given MediaDrm instance map to a given CdmEngine instance.

Bug: 73724453
Test: Updated unit tests. GTS test pass. Shaka Player, Netflix and Google Play test.
Change-Id: I7e041b6cdf3e272d067da49d25a297b4a4663f1f

libwvdrmengine/mediadrm/include_hidl/WVDrmPlugin.h

@@ -365,6 +365,10 @@ struct WVDrmPlugin : public IDrmPlugin, IDrmPluginListener,
     const std::string& origin() const { return mCdmIdentifier.origin; }
     bool set_origin(const std::string& id);
 
+    // Indicates whether the builder can still be modified. This returns false
+    // until a call to getCdmIdentifier.
+    bool is_sealed() { return mIsIdentifierSealed; }
+
    private:
     WVDRM_DISALLOW_COPY_AND_ASSIGN(CdmIdentifierBuilder);
 
@@ -382,6 +386,13 @@ struct WVDrmPlugin : public IDrmPlugin, IDrmPluginListener,
     // outside this class should use getDeviceUniqueId() to get the
     // application-safe device-unique ID.
     Status getOemcryptoDeviceId(std::string* id);
+
+    // The unique identifier is meant to ensure that two clients with the
+    // same spoid, origin and app package name still get different cdm engine
+    // instances. This is a stepping stone to simplifying the implementation.
+    // Note that we do not have a lock or mutex around this object. We assume
+    // that locking is handled external to this object.
+    uint32_t getNextUniqueId();
   } mCdmIdentifierBuilder;
 
   sp<wvcdm::WvContentDecryptionModule> const mCDM;