Direct connection btw Autofill & Credman sessions

Before this change, a result reciever was added to each pinned dataset's
associated intent, and then retrieved in the from the intent that
starts the credman selector intent which then passed it to credman session.
Now, autofill session constructs one resultreciever per FillRequest and adds it to
client state, proxy service retrieves it from clientstate and
adds it to the req top level bundle, which is then extracted by credman session
and used to propagate the final response.
Hence we remove the dependency on the selector passing the resultReciver to the credman
session

Test: Cts
Bug: 333455221

Change-Id: Ic17091841edbcf0975d0ff238f2d8b72d8cd5593