Set objects indirection API in network service

We need to set the
nova.objects.baseNovaObject.indirection_api global inside the network
service to point to the conductor API so that the object actions will
 be done by RPC to conductor.

Part of blueprint: nova-network-objects

Change-Id: I9e2c643eae7d09f5037485386e6ea53b75587980
Merge "Set objects indirection API in network service"