[roll + cherry pick] Fix imports for FlutterApplication (#40100)

[XilaiZhang]

Fix imports for FlutterApplication

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[flutter-dashboard]

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[XilaiZhang]

looks like engine auto roller still hasn't rolled the change to framework. will do an engine cherry pick

[XilaiZhang]

windoes arm host engine failed 4 times in a row but i am pretty sure this is a flake

[XilaiZhang]

will merge

[CaseyHillers]

@XilaiZhang you can skip presubmits on roll CPs.