Add transition period for internet charges

Why is this change being made?

This MR introduces a transition period for the newly introduced limit on internet charges, allowing team members that entered into a contract with a minimum term to expense the full charge until the minimum term is concluded.

My provider only offers contracts with a minimum 2-year term. Since I live in Germany, Fibre is expensive for some reason and easily exceeds the 80$ limit. But since a fibre connection is industry standard for remote work where available and GitLab both primarily benefits from it and covered the cost, I opted for it. I don't do a lot of streaming, so my personal benefit from that connection is negligible.

Now GitLab changed the expense policy and I am stuck in an expensive contract that only GitLab benefits from but stopped covering. This MR would allow me to continue to have the costs covered until I am able to downgrade back to Copper.

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