fix(fab): apply safe area in positioning to proper side regardless of direction (#28377)

Issue number: Internal

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## What is the current behavior?
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When calculating the fab's horizontal position, the safe area is taken
into account. However, which safe area side is applied changes depending
on whether the document's direction is LTR or RTL. This is incorrect as
the left safe area padding will always be on the left side regardless of
direction, and vice versa.

## What is the new behavior?
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this PR. -->

The left safe area is always applied to the fab's `left` position, and
vice versa.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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and migration path for existing applications below. -->


## Other information

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screenshots of how the component looks before and after the change. -->

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Co-authored-by: ionitron <hi@ionicframework.com>