Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1308860
Description of problem:
User is able to set the default value for parameter even if the 'override' flag is not set for the parameter, which is not expected.
Note: This issue is only observed in CLI and not in UI.

Version-Release number of selected component (if applicable):
foreman-1.11.0-0.develop.201601251557git59dc77b.el6.noarch

How reproducible:
Always

Steps to Reproduce:
1. Attempt to set default value for parameter which override flag is set to False.

Actual results:
Default Value successfully updated and no error raised.

Expected results:
1. Error/Info should be raised to set the 'override' flag to True first.
2. Default Value should not be updated.

Additional info: