fix(SafeAreas): fix iOS fallback (#29941)

Issue number: internal

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- fix ion-statusbar css var fallback;


## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->
- CSS var --ion-statusbar-padding was not working because the Sass
variable was not escaped.


## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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