fix(messaging, ios): foreground notification appears twice on iOS 18 #387

Job	Run time
macos (tests)	21m 3s
macos (tests)	14m 21s
macos (tests)	14m 43s
macos (packages/cloud_firestore/cloud_firestore/example)	12m 57s
macos (packages/cloud_firestore/cloud_firestore/example)	12m 57s
macos (packages/cloud_firestore/cloud_firestore/example)	12m 57s
	1h 28m 58s

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