[core] Use dynamic chunk size for downloading maps

Signed-off-by: Konstantin Pastbin <konstantin.pastbin@gmail.com>

android/app/src/main/cpp/app/organicmaps/DownloadResourcesLegacyActivity.cpp

@@ -171,7 +171,7 @@ extern "C"
           curFile.GetRemoteSize(),
           std::bind(&DownloadFileFinished, ptr, _1),
           std::bind(&DownloadFileProgress, ptr, _1),
-          512 * 1024, false));
+          0, false));
     });
 
     return ERR_FILE_IN_PROGRESS;