[Imprv] add functionality start_time idempotency check to module protection_rules.py

[stahnjones]

Describe the request
Add idempotency check against the start_time field

Current behaviour
idempotency check does not check the start_time field when comparing if the requested definition is different than the current definition

Expected behaviour
idempotency check compares the start_time field between existing and requested definitions and updates the current definition if the start_time field has been changed

[stahnjones]

stahnjones#2