Update demo features for switch to ondemandnavi

Update demo features for switch to ondemandnavi

The ondemandnavi navigation application does not work with the
mapviewer cluster demo application, so update the logic to handle
the agl-cluster-demo-support feature in packagegroup-agl-demo-platform
to not pull it in when using ondemandnavi as the virtual/navigation
provider.  Since the plan is to replace mapviewer with an equivalent
QtLocation based map streamer for the cluster demo, the mapviewer-demo
recipe has also been replaced with a more generically named
cluster-demo-network-config recipe.  Additionally, the agl-demo-preload
feature logic has been tweaked to not pull in the map package for the
old navigation application when using ondemandnavi.

Bug-AGL: SPEC-2576

Change-Id: I57b45ab152f9fab6cee97d570be1949136cd39eb
Signed-off-by: Scott Murray <scott.murray@konsulko.com>