Race in hfp call termination when local termination faster than HFP

update.

If we make a call from the CarKitt and terminate it immidiately then the
CarKitt assumes no call has been created since phone hasnt replied yet
to the message from CarKitt. When it does reply, the CarKitt throws that
message away because it did not handle the intermediate state of
disconnection properly.

Bug: b/28122608

Change-Id: I98105fd36914612fc96cba4d56db97b342822ffa
(cherry picked from commit 52297bafb15107ef66b7edeb1879df28b26e5cc9)