[Delivers #49344721 Fix Volume - Attachment property to resolve serialization issues

**Summary**
This will resolve an issue for the Cloud Block Storage provider when it is attempting to serialize the volume object's "Attachments" property.  Currently the "Attachments" property is currently set as a string array and it needs to be a dictionary<string,string> to be able to handle what is being sent from the API correctly.

**Testing**
Ran full integration tests and all passed.