Remove redundant MediaQueryDatas in tests

[nt4f04uNd]

MaterialApp provides MediaQueryData from window, no need to create one unless we change it

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[Piinks]

Hey @nt4f04uNd this is a great PR! LGTM! Thank you for cleaning up these tests. Can you rebase with master to bring this up to date? It looks like it has been a while and I'd hate for it to get reverted due to a change at TOT. Thanks!