Allow for call direction updates in Telecom

In single party call emulation during conference calling, the
conference itself becomes a "single party call". The call direction
of the call should also be passed correctly to Telecom or the
call will be incorrectly logged as an outgoing call every time.

Bug: 153277327
Test: atest TelecomUnitTests
Change-Id: I622a3ae877067c6f5f9a4830f4c46469f9f93e21