Check the network_info obj type before invoke wait function

When instance schedule to host and it isn't first time schedule,
the instance may already allocated network. And then the code
will return an NetworkInfo object, not an NetworkInfoAsyncWrapper.
The checking code only assume it is NetworkInfoAsyncWrapper object.

Change-Id: I987902fc47e509e4fd08f762d66b16c09eaf5008
Partial-Bug: #1326207
Merge "Check the network_info obj type before invoke wait function"