Summary:
Changing these object arguments to `$ReadOnly` permits passing in values that are `$ReadOnly` (e.g. `payload` argument to `enqueueNativeEvent`).
Changelog:
[Internal]
Reviewed By: lyahdav
Differential Revision: D72474879
fbshipit-source-id: 27341131724f4f572b78563975774a5b20dee8f8