CLOUDSTACK-4065: db upgrade - when insert placeHolder nic for Shared networks, always mark this nic as non-default explicitly

Conflicts:
	engine/schema/src/com/cloud/upgrade/dao/Upgrade410to420.java
remove hardcoded vlan for shared network test

use a vlan outside of the vlans managed by cloudstack.

Signed-off-by: Prasanna Santhanam <tsp@apache.org>