Make cells use Fault obj for create

Add support into InstanceFault.create() to handle where we need to
duplicate any faults in the API cells. Convert the cells code to use
InstanceFault.create()

NOTE: This happens to fix an oversight where we accidentally left the
update_cells=False kwarg off of the db call in the cells code.

Change-Id: Iec11b8259aaecba055a6d5636ab60dfa0dbb6c83
Merge "Make cells use Fault obj for create"