This is one fragment that holds all types of
authentication information, e.g. password,
OAuth info, and client certificates. What gets
displayed depends upon the type of account it is
dealing with.
So far this is only used in AccountSetupIncoming,
but later it can be added to other settings fragments.
There are still some issues with this, but I'd like
to check it in sooner than later to unblock other
work.
Change-Id: Iea675ad5c1727f32ca0baa270dfa793ab7109993
