Add flag to control default assisted dialing state during precall flow.

Currently, the only other client that is initiating
calls is Contacts, and we consider that to be a
non-idle-dial.
Bug: 69860859
Test: existing unit tests
PiperOrigin-RevId: 177367226
Change-Id: I22de38dc973f5a1eecfe42833110690744c317fd
1 file changed