fix: build settings for custom build configuration (#43780)

Summary:
This allows build configuration named like `StagingDebug` to match with settings applied to `Debug` This fixes https://github.com/facebook/react-native/issues/43185

Custom build setting were only applied to `Debug` build configurations, preventing configurations named `StagingDebug` or similar to access the new experimental debugger, as reported in https://github.com/facebook/react-native/issues/43185

This now applies the setting to every configuration ending with `Debug`

## Changelog:

[IOS] [CHANGED] - fix: build settings for custom build configuration

Pull Request resolved: https://github.com/facebook/react-native/pull/43780

Reviewed By: dmytrorykun

Differential Revision: D55688996

Pulled By: cipolleschi

fbshipit-source-id: 1f34cd722f6acfaa08d3377e19a04d08af97ed7c