feat(brightness suw): adjust brightness toggles UI and remove autobrightness standalone page

Based on the UX alignment in doc and figma, we remove the autobrightness
detailed page to make the consistency with other Vision settings, and
update the brightness preference icons and summaries.

Bug: 377289685
Flag: com.android.settings.accessibility.add_brightness_settings_in_suw
Test: manually
Change-Id: If4038de07dec7eeb38d3c057affba737849e23c9