Merge sub pages for lock/unlock into 1 xml.

And create PreferenceControllers for each setting

The page is still pretty janky and controllers are invoked manually.
Next CL will clean these up.

Bug: 32953042
Test: TODO
Change-Id: I1d7478324f5de4fdb464d79f89086f7e79c0ee67

src/com/android/settings/display/AutoBrightnessPreferenceController.java

@@ -45,9 +45,10 @@ public class AutoBrightnessPreferenceController extends TogglePreferenceControll
     }
 
     @Override
-    public void setChecked(boolean isChecked) {
+    public boolean setChecked(boolean isChecked) {
         Settings.System.putInt(mContext.getContentResolver(), SYSTEM_KEY,
                 isChecked ? SCREEN_BRIGHTNESS_MODE_AUTOMATIC : DEFAULT_VALUE);
+        return true;
     }
 
     @Override