What would you do if your Principal made a decision you did not like?

At this point, if you have a feel for the principal's leadership style, try to say something that aligns with that style. Be honest about how you react to decisions you disagree with. Seeing multiple perspectives is important in education because unpopular decisions have to be made often.
If you are a more agreeable person, explain your view on leadership and lay out the actions that you would perform.
If you are a less agreeable person, be forthright about it and move quickly to demonstrate your professionalism and ability to defer to authority.
Either way, it's important to express a willingness to put aside your temporary differences to act towards a common overarching goal.