Description of problem:
vm.storage only returns one storage id instead of list of storage ids that are associated with VM object.

Version-Release number of selected component (if applicable):
5.9

How reproducible:
Always

Steps to Reproduce:

1. Create a VM under Vmware provider and another hard disk under different storage domain then the one where VM is deployed. In that way, you will have multiple storage ids associated with that vm.

2. Go to Rails console and perform below commands:

# vmware = $evm.vmdb('ems').find_by_name('vmware-admin') ; 
# vm = vmware.vms.select { |v| v.name == 'nchugh-cfme59' }.first ; 
# vm.storage ( only one storage id returns)

Though the vm object is associated with multiple storage ids but it shows only one storage id in which Vm is deployed. 

But VM's active record object has inbuilt method i.e. "storage_ids" which provides the list of storage ids associated with it.

#vm = VmOrTemplate.find_by_id(<vm id>)
#vm.storage_ids ( will list out the storage ids assciated with it)

We cannot use Active record object types directly in the automation so we need inbuilt functionality under service model object which can provide the list of the storage ids.

Actual results:
It returns only one storage id where the VM is deployed.

Expected results:
Vm.storage should return the list of storage ids associated with the VM.

Additional info: