fix: prevent ExpandableOverlay onDismiss callback from being called twice

[adids1221]

Description

Fixes an issue where the onDismiss callback passed via modalProps or dialogProps was being called twice when the overlay was dismissed.

The issue occurred because closeExpandable was being triggered from multiple sources:

1. From onBackgroundPress / onRequestClose when user dismissed the modal
2. From React Native Modal's internal onDismiss callback

Added a new dismissOverlay function that only closes the UI without calling the user's callback. Modal's onDismiss now uses dismissOverlay, while onBackgroundPress and onRequestClose continue to use closeExpandable.

Verified that components using ExpandableOverlay are not affected:

• Picker - all tests pass
• DateTimePicker - all tests pass

Changelog

ExpandableOverlay - Fixed onDismiss callback being called twice when modal is dismissed.

Additional info

MADS-4656
Old PR (Closed because of conflicts, all the comments there are fixed here)

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