Providing reference on resource during preview

There are several resources which use physical_resource_name to provide
reference to itself. However these resources have no 'id' attribute
during preview process and returns None. This patch adds new function
physical_resource_name_or_FnGetRefId that calls FnGetRefId method of
Resource class if physical_resource_name is None.

Change-Id: I0e61743d5c105391eaec4c28150dddeee8a938bd
Merge "Providing reference on resource during preview"