chore(core): Bump sample app to React Native 0.84.1 #12756

Job	Run time
Ready-to-merge gate / Missing "ready-to-merge" label	3s
diff_check / diff_check	9s
detect-changes / Detect file changes	5s
Build new android dev	11m 22s
Build legacy macos production	5m 36s
Build legacy macos dev	5m 36s
Build legacy android production	8m 56s
Build legacy ios production dynamic-frameworks	1m 29s
Build legacy android dev	8m 28s
Build new android production	11m 24s
Build legacy ios dev no-frameworks	1m 35s
Build new ios dev no-frameworks	7m 7s
Build new ios production no-frameworks	7m 9s
Build legacy ios dev dynamic-frameworks	1m 38s
Build legacy ios production no-frameworks	1m 32s
Test ios production REV2	0s
Test android production REV2	1s
	1h 12m 10s

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