[Barcode Scanner] Implement Fallback to Front-Facing Camera if Back Camera is Unavailable

[AnirudhBhat]

Closes: #13174

Description

This PR updates the barcode scanner to gracefully handle devices where a back-facing camera is unavailable, such as Chromebooks. The code now checks for available cameras and falls back to the front-facing camera if necessary.

Steps to reproduce

Devices that have both back and front facing camera

1. Navigate to Orders tab
2. Click on the barcode icon in the toolbar
3. Ensure barcode scanner works as expected

Devices that have doesn't have back facing camera (Chromebook)

1. Navigate to Orders tab
2. Click on the barcode icon in the toolbar
3. Ensure barcode scanner works as expected

The tests that have been performed

Simulated Testing: Modify the code to skip the back camera temporarily and test fallback to the front camera.

• I have considered if this change warrants release notes and have added them to RELEASE-NOTES.txt if necessary. Use the "[Internal]" label for non-user-facing changes.

Reviewer (or Author, in the case of optional code reviews):

Please make sure these conditions are met before approving the PR, or request changes if the PR needs improvement:

• The PR is small and has a clear, single focus, or a valid explanation is provided in the description. If needed, please request to split it into smaller PRs.
• Ensure Adequate Unit Test Coverage: The changes are reasonably covered by unit tests or an explanation is provided in the PR description.
• Manual Testing: The author listed all the tests they ran, including smoke tests when needed (e.g., for refactorings). The reviewer confirmed that the PR works as expected on big (tablet) and small (phone) in case of UI changes, and no regressions are added.

[wpmobilebot]

📲 You can test the changes from this Pull Request in WooCommerce-Wear Android by scanning the QR code below to install the corresponding build.

	App Name	WooCommerce-Wear Android
	Platform	⌚️ Wear OS
	Flavor	Jalapeno
	Build Type	Debug
	Commit	26fa3f2
	Direct Download	woocommerce-wear-prototype-build-pr13230-26fa3f2.apk

[wpmobilebot]

📲 You can test the changes from this Pull Request in WooCommerce Android by scanning the QR code below to install the corresponding build.

	App Name	WooCommerce Android
	Platform	📱 Mobile
	Flavor	Jalapeno
	Build Type	Debug
	Commit	26fa3f2
	Direct Download	woocommerce-prototype-build-pr13230-26fa3f2.apk

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 8 lines in your changes missing coverage. Please review.

Project coverage is 40.64%. Comparing base (bcbbde1) to head (26fa3f2).

Files with missing lines	Patch %	Lines
...mmerce/android/ui/barcodescanner/BarcodeScanner.kt	0.00%	8 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##              trunk   #13230      +/-   ##
============================================
- Coverage     40.64%   40.64%   -0.01%     
+ Complexity     6387     6386       -1     
============================================
  Files          1351     1351              
  Lines         77444    77451       +7     
  Branches      10650    10652       +2     
============================================
- Hits          31479    31478       -1     
- Misses        43186    43193       +7     
- Partials       2779     2780       +1     

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