Fix # 7605: Camera view is rotated to 90 degrees in "Scan QR Code" UI when a device in Landscape Mode

[soner-yuksel]

Adding viewWillTransition change for orientation in preview video layer orientation change

Summary of Changes

This pull request fixes #7605

Submitter Checklist:

• Unit Tests are updated to cover new or changed functionality
• User-facing strings use NSLocalizableString()
• New or updated UI has been tested across:
  • Light & dark mode
  • Different size classes (iPhone, landscape, iPad)
  • Different dynamic type sizes

Test Plan:

1. Launch Brave
2. URL search bar > Remove URL
3. Tap QR code thumbnail
4. When Scan QR Code UI is opened rotate the device to Landscape Mode > Observe

Screenshots:

RPReplay_Final1687457608.MP4

Reviewer Checklist:

• Issues include necessary QA labels:
  • QA/(Yes|No)
  • bug / enhancement
• Necessary security reviews have taken place.
• Adequate unit test coverage exists to prevent regressions.
• Adequate test plan exists for QA to validate (if applicable).
• Issue and pull request is assigned to a milestone (should happen at merge time).