Earpiece availability from audio config (vs hard coded)

Teach the call routing state machine to respect the available hardware
devices instead of hard coding based on target platform when deciding if
an earpiece is avaiable. Updates the tests which relied on hard coded
values to work with the new calling convention.

Note that serval approaches to mocking the AudioManager were tried that
would have allowed removal of the extra constructor parameter updated in
this CL and used only for testability.  All were thwarted by private
final classes.

Test results:  Ran 17 tests for TelecomUnitTests. 17 passed, 0 failed

Bug: 65614292
Test: bit TelecomUnitTests:CallAudioRouteStateMachineTest
Change-Id: Icdb9a03cefd3e4d399fe8cd878c61524e1000d95