Move bearer token parameter setup into from setupRequestAuth to getBearerToken
Move bearer token parameter setup into from setupRequestAuth to getBearerToken

This is a trivial move, does not change behavior; but it will allow
setupRequestAuth to be a bit more complex about the scopes and token caching
in the future.

Signed-off-by: Miloslav Trmač <9c008e38982a5397deb855345fb164f0558459ae@redhat.com>

containers/image,containers/image