Summary:
I've noticed that `BackHandler.removeEventListener()` performs two same `indexOf()` calls on an array that is not changing. By removing extra `indexOf` we can slightly improve time complexity of `BackHandler.removeEventListener()` from O(2n) to O(n)
## Changelog
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[Android] [Fixed] - Remove extra indexOf call in BackHandler.removeEventListener
Pull Request resolved: https://github.com/facebook/react-native/pull/34281
Test Plan:
1. Add the following code to any function component
```javascript
BackHandler.addEventListener('hardwareBackPress', () => true).remove();
```
2. Press on hardware back button
Expected result: Application closes
Reviewed By: dmitryrykun
Differential Revision: D38198510
Pulled By: javache
fbshipit-source-id: eab6a57689a536623138a4b3ebddbf9ba87d281f
Vitalii T
14c207d9e1