I successfully import the project to google cloud. I am running android studio on a Mac. But, when i try to push the project to the cloud repository i get the error:
For osx on Mac...this drove me bananas! I went to Keychain > All items > deleted the entry under "GitHub - source.developers.google.com/[your repo address]" and then tried again.
You have to have gone through this process first to ensure you have the Manual Credentials set up, but I'm sure you knew this already.