Retry provisioning and license requests on 502 errors

[ Merge of http://go/wvgerrit/219370 ]

Work around the server problem.

Bug: 345333545
Change-Id: Ie1b0021f545c77d61bb2363494239f4fe000f3d5

libwvdrmengine/cdm/core/test/url_request.h

@@ -29,7 +29,8 @@ class UrlRequest {
   bool GetResponse(std::string* message);
   static int GetStatusCode(const std::string& response);
   // Get the response, and expect the status is OK.
-  void AssertOkResponse(std::string* message);
+  // It will retry if the response code is in the 500 range.
+  void AssertOkResponseWithRetry(std::string* message);
 
   static bool GetDebugHeaderFields(
       const std::string& response,
@@ -37,9 +38,11 @@ class UrlRequest {
 
  private:
   bool PostRequestWithPath(const std::string& path, const std::string& data);
+  bool SendRequestOnce();
 
   bool is_connected_;
   HttpSocket socket_;
+  std::string request_;
 
   CORE_DISALLOW_COPY_AND_ASSIGN(UrlRequest);
 };