[screen-orientation][ios] Fix config plugin deleting the EXDefaultScreenOrientationMask key from Info.plist (#23637)

# Why

https://github.com/expo/expo/issues/23141
When the `initialOrientation`

[screen-orientation][ios] Fix config plugin deleting the EXDefaultScreenOrientationMask key from Info.plist (#23637)

# Why

https://github.com/expo/expo/issues/23141
When the `initialOrientation` value was set to `"DEFAULT"` the config
plugin would delete the `EXDefaultScreenOrientationMask` key from
`Info.plist`.

# How

Made the config plugin delete the key only if it isn't not configured

# Test Plan

Tested on iOS 16 simulator

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Co-authored-by: Expo Bot <[email protected]>

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