Add config_speed_up_audio_on_mt_calls option

Bug: 7612431
Change-Id: Ia2758f81b78a2576df8dd23c700dba3eaaef8efc

Conflicts:
	core/res/res/values/config.xml

Conflicts:
	core/res/res/values/config.xml
	core/res/res/values/symbols.xml