Refactor CameraActivity to Controller and ViewModel architecture

- Refactored CameraActivity to CameraController and CameraViewModel with Compose UI.
- Used ImageDecoder to correctly orient and decode captured photos.
- Handled photo capture via background executor to prevent stalls.
- Managed CameraX lifecycle strictly within Controller scope.

Test: ./gradlew :xr:projected:integration-tests:testapp:lintDebug
Test: ./gradlew :xr:projected:integration-tests:testapp:assembleDebug
Relnote: N/A
Change-Id: I6da7d7cf286f254d73e229c77c6f2b00aea40c40