Add vendor-specific command API for HdmiControl

Vendor-specific commands are not handled by the service. This CL
opens an API for vendors to implement customized handling of
CEC commands specific to their needs.

Change-Id: I8bfa3b891bd7994a903b3b41d7c2b27464167afa
diff --git a/Android.mk b/Android.mk
index 581f2da..6859678 100644
--- a/Android.mk
+++ b/Android.mk
@@ -153,6 +153,7 @@
 	core/java/android/hardware/hdmi/IHdmiHotplugEventListener.aidl \
 	core/java/android/hardware/hdmi/IHdmiInputChangeListener.aidl \
 	core/java/android/hardware/hdmi/IHdmiSystemAudioModeChangeListener.aidl \
+	core/java/android/hardware/hdmi/IHdmiVendorCommandListener.aidl \
 	core/java/android/hardware/input/IInputManager.aidl \
 	core/java/android/hardware/input/IInputDevicesChangedListener.aidl \
 	core/java/android/hardware/location/IFusedLocationHardware.aidl \