Replace migration test examples

What does this MR do and why?

Two of the examples used for migration testing have hardcoded id fields used in test data setup. This is generally not a recommended practice in tests and can cause brittleness (examples: #205219 (comment 286997549), !42200 (comment 417469776))

This MR replaces the two examples with examples of tests that do not use hardcoded ids.

Screenshots or screen recordings

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How to set up and validate locally

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MR acceptance checklist

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