Description of problem:
The size of PVC has no validation in the Create host form

production.log
```
 <Kubeclient::HttpError> PersistentVolumeClaim in version "v1" cannot be handled as a PersistentVolumeClaim: v1.PersistentVolumeClaim.Spec: v1.PersistentVolumeClaimSpec.AccessModes: []v1.PersistentVolumeA
ccessMode: Resources: v1.ResourceRequirements.Requests: unmarshalerDecoder: quantities must match the regular expression '^([+-]?[0-9.]+)([eEinumkKMGTP]*[-+]?[0-9]*)$', error found in #10 byte of ...|rage":"xG"}
},"access|..., bigger context ...|s-storage","resources":{"requests":{"storage":"xG"}},"accessModes":["ReadWriteOnce"]}}|...
```

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

How reproducible:


Steps to Reproduce:
1.Go to create a host
2.Under Virtual Machine tabs, add storage with wrong values
3.

Actual results:
Does not have validation, and causes wrong exception due to size format being wrong

Expected results:
Should give proper exception if the format of the entry was wrong

Additional info: