[0.78] Allow multiple RN instances to run at the same time with the same feature flags

[cipolleschi]

Target Branch(es)

0.78

Link to commit or PR to be picked

facebook/react-native@444c7d4

Description

There are use cases where users might want multiple React Native instance running at the same time in their app. Expo, for example, needs multiple instances in Expo Go and with their dev client.

Without this fix, this is not possible, because the app will crash trying to override the feature flags a second time. However, we know that overriding the feature flags with the same values is same and it should be allowed.

This fix allow users to spawn multiple React Native instances with the same feature flags.

[react-native-bot]

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