Improves unit test coverage for dcmanager's orchestrator/states/firmware
functionality from 70% to 100%.
Test plan:
All of the tests were created taking into account the
output of 'tox -c tox.ini -e cover' command
Story: 2007082
Task: 49312
Change-Id: I00895fb7616d0c3eeb54f623a8a1ccd223169bd9
Signed-off-by: rlima <Raphael.Lima@windriver.com>