Bug: Multiple taps on “Close” button cause camera view to stagger / freeze momentarily

## Description
When the user taps the Close button multiple times in quick succession within the AzureAIVisionFaceUI framework, the camera preview becomes staggered or momentarily freezes. This suggests that multiple dismissal or teardown actions may be triggered simultaneously.

## Steps to Reproduce
1. Launch Demo app
2. open Liveness tab
3. Rapidly tap the Close button several times.
4. Observe the camera preview.
See attached screen [Recording](https://drive.google.com/file/d/1TW7WM4wgJMMnwJV8VePvrPCr3avCk2Vl/view?usp=sharing)

## Expected Behavior
The camera should close cleanly on the first tap.
Additional taps should be ignored while the dismiss/teardown process is in progress.
No staggering, freezing, or UI glitches should occur.

## Actual Behavior
Camera preview stutters or staggers after multiple rapid taps.
UI may briefly freeze before dismissing.
Reinit of LivenessView broken

## Environment
AzureAIVisionFaceUI version: 1.4.5
Device model: iPhone 14 Pro
OS version: iOS 26.1