Log a different message for policy jobs with highest precedence
What does this MR do?
Log a different message for policy jobs with highest precedence.
When variables_override option is not specified for the policy, the behavior is slightly different than ignoring all user-defined variables.
This change adds a specific message for this case to be more factually correct.
Why was this MR needed?
The currently logged message is factually incorrect in one specific case:
While it's partially true that other values are ignored thanks to the highest precedence, we don't ignore all user-defined variables. Users have to specify the variables in their policy configurations to enforce them.
More context is provided in this comment: gitlab#541922 (comment 2548908323)
