WV DRM plugin stubs to report key request type for unprefixed EME

This CL allows the framework CLs to compile.  The stubs need to
be implemented properly in the DRM plugin and CDM.

bug: 19771299
Change-Id: I9e4b107370a4d73851ee28bcb9ab6087fdffeb13

libwvdrmengine/mediadrm/include/WVDrmPlugin.h

@@ -59,7 +59,8 @@ class WVDrmPlugin : public android::DrmPlugin,
       KeyType keyType,
       const KeyedVector<String8, String8>& optionalParameters,
       Vector<uint8_t>& request,
-      String8& defaultUrl);
+      String8& defaultUrl,
+      KeyRequestType *keyRequestType);
 
   virtual status_t provideKeyResponse(const Vector<uint8_t>& scope,
                                       const Vector<uint8_t>& response,