Downloading https://dl.google.com/android/repository/91936d4ee3ccc839f0addd53c9ebf087b1e39251.build-tools_r30.0.3-windows.zip code example

Example: where to place /android/repository/emulator-windows-6962233.zip file

I had this similar issue below worked for me. The solution for this is:

1. Run Android Studio as Administrator.
2. Re run the update.

reference : https://stackoverflow.com/questions/43705311/error-with-sdk-package-download-in-android-studio