Sends signed provisioning request as query string instead of payload.

Bug: 8790775

Merge of https://widevine-internal-review.googlesource.com/#/c/5381/
from the Widevine CDM repository.

Change-Id: I749303eee8162f37982f6dd5d83b6cf254b96847

libwvdrmengine/cdm/core/test/url_request.h

@@ -17,12 +17,11 @@ class UrlRequest {
   ~UrlRequest();
 
   void AppendChunkToUpload(const std::string& data);
-  void AppendData(const std::string& data);
   int  GetResponse(std::string& response);
   int  GetStatusCode(const std::string& response);
   bool is_connected() const { return is_connected_; }
   bool PostRequest(const std::string& data);
-  bool PostCertRequest(const std::string& data);
+  bool PostCertRequestInQueryString(const std::string& data);
 
  private:
   static const unsigned int kHttpBufferSize = 4096;