Add recipe for demo voice capabilities GUI metadata event viewer for
Alexa voiceagent, and conditionally add it to the list of applications
in packagegroup-agl-demo-platform based on the agl-voiceagent-alexa
feature being present in IMAGE_FEATURES.
Bug-AGL: SPEC-3110
Change-Id: I7b84ace51430937dbcb35f4773b06290039a19bd Signed-off-by: Scott Murray <scott.murray@konsulko.com>