audiopolicy: Do not route VoIP call to HDMI

getDeviceForStrategy is returning AUDIO_DEVICE_OUT_AUX_DIGITAL
even  when setForceUse is called with FORCE_NONE(earpiece)
during VOIP call.
Actual Intention is to route audio for phone strategy to AUX
device even after setForceUse is called with FORCE_NONE when not
in voice call. It is supposed to exclude VOIP call too.

Bug: 19522164.

Change-Id: I88d515c351f066305f9eed240b1fe5f60ef34f85