Fix getConnectionToSinkType for internal displays

The relative address is only populated for HDMI displays, which caused
the API to return UNKNOWN for other (e.g. DSI, eDP) internal displays.
Report CONNECTION_TO_SINK_BUILT_IN for a matching HAL connection type.

Fixes: 376046748
Flag: EXEMPT bugfix
Test: manual
Change-Id: I0dde33d31f17753a2a1bf4ce421dc0d002bed108