Pass old Credentials to CredentialRefreshListener when token refreshed

[bedla]

Hi,
I think that order of setting new refresh token and calling listener should be switched in method com.google.api.client.auth.oauth2.Credential#refreshToken.
Currently first is setFromTokenResponse called and second refreshListener.onTokenResponse is called. Method setFromTokenResponse changes currently Credential instance and this side-effected instance is passed to onTokenResponse.
My use-case is that I want to check/"pass somewhere" old tokens in listener and because of this order I am unable to get valid old tokens from Credential instance.
Is this behaviour intentional or I found bug? I can create PR.
Thx,
Ivos