Add the definitions as to 3ch and 4ch audio

Update TypeConverter since new channel masks are added to system/audio.
Add the following values to OutputChannelConverter::mTable[].
 - AUDIO_CHANNEL_OUT_TRI
 - AUDIO_CHANNEL_OUT_TRI_BACK
 - AUDIO_CHANNEL_OUT_3POINT1

Test: make
Change-Id: I2112a137a94a7ed431f47e46477c6e3a728ddf16