Pass objects for revert and confirm resizes

The revert_resize and confirm_resize compute API methods were previously
converted to accept and use objects.  This actually passes them over RPC
instead of their primitive forms.

Implements blueprint unified-object-model

Change-Id: I6dbd5fc0ddcaa37013e885b71aabede92eedf120
Merge "Pass objects for revert and confirm resizes"