[camera_android_camerax] Prefer higher resolution for max preset (#11956)

Updates `camera_android_camerax` so `ResolutionPreset.max` can select Camera2 high-resolution JPEG still capture sizes on Android. For `ResolutionPreset.max`, `ImageCapture` now uses `ResolutionSelector.PREFER_HIGHER_RESOLUTION_OVER_CAPTURE_RATE`; preview and image analysis keep the existing selector without high-resolution mode.

Fixes flutter/flutter#188310

## Problem

On some Android devices, Camera2 exposes the largest 4:3 still resolution only through `getHighResolutionOutputSizes(ImageFormat.JPEG)`. The CameraX backend used `ResolutionStrategy.HIGHEST_AVAILABLE_STRATEGY` without `ResolutionSelector.PREFER_HIGHER_RESOLUTION_OVER_CAPTURE_RATE`, so CameraX could pick the largest regular JPEG size instead.

## Observed

- Camera2 regular JPEG max: 3264x2448
- Camera2 high-resolution JPEG: 4624x3468
- Flutter `takePicture()`: 2448x3264

## After fix

- CameraX `ImageCapture`: 4624x3468
- Flutter `takePicture()`: 3468x4624

## Risk / tradeoff

High-resolution still capture can be slower and use more memory. Limited to `ResolutionPreset.max` and `ImageCapture` only.

## Note

Generated Pigeon files (`camerax_library.g.dart`, `CameraXLibrary.g.kt`) include formatting churn from local pigeon regeneration; functional changes are limited to `ResolutionSelector` allowed resolution mode and max-preset ImageCapture selector behavior.

## Pre-Review Checklist

## Test plan