Add API to get Auth Token Type used by authenticator.

When using different auth protocols e.g. ClientLogin and
OAuth2 it is important to know the type of the token in order
to construct "Authorization" header. Currently we have to
store auth token vaue/auth token type association elsewhere
which makes it a subject for errors.

Change-Id: I3b8c05672f5394ad806f257c9f6bb378ebf990d7
1 file changed