[DM]: Do not assume vmi device_owner attribute is always set by api c…

…lients

If not set, set it to ''. Also alow to have device owner attribute value can be PhysicalRouter or physical-router

Change-Id: I2ebef4d16ae8739a4d8a63b125b4aa880fb7d58e
Partial-Bug: #1646684

src/config/device-manager/device_manager/db.py

@@ -1039,7 +1039,7 @@ def update(self, obj=None):
             self.params = obj['virtual_machine_interface_properties']
             self.service_interface_type = self.params.get(
                 'service_interface_type', None)
-        self.device_owner = obj.get("virtual_machine_interface_device_owner")
+        self.device_owner = obj.get("virtual_machine_interface_device_owner") or ''
         self.update_single_ref('logical_interface', obj)
         self.update_single_ref('virtual_network', obj)
         self.update_single_ref('floating_ip', obj)
@@ -1055,7 +1055,7 @@ def update(self, obj=None):
     # end update
 
     def is_device_owner_bms(self):
-        if self.logical_interface and self.device_owner.lower() == 'physicalrouter':
+        if self.logical_interface and self.device_owner.lower() in ['physicalrouter', 'physical-router']:
             return True
         return False
     # end