Add support for device state based auto-rotation preferences in Settings.

- Creates new preferences that are shown when device-state rotation
  is supported.
- Hides standard preferences when device-state rotation is supported.
- Controllers/Preferences for individual folded/unfolded rotation
  settings are created and added programatically based on the settable
  device states available.

Test: Manually + Unit tests
Bug: 195757480
Change-Id: If254220ca3018bc6ec1c4e3947375733f6816f92

src/com/android/settings/dashboard/DashboardFragment.java

@@ -53,6 +53,7 @@ import com.android.settingslib.utils.ThreadUtils;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -280,6 +281,11 @@ public abstract class DashboardFragment extends SettingsPreferenceFragment
         return null;
     }
 
+    /** Returns all controllers of type T. */
+    protected <T extends AbstractPreferenceController> List<T> useAll(Class<T> clazz) {
+        return (List<T>) mPreferenceControllers.getOrDefault(clazz, Collections.emptyList());
+    }
+
     protected void addPreferenceController(AbstractPreferenceController controller) {
         if (mPreferenceControllers.get(controller.getClass()) == null) {
             mPreferenceControllers.put(controller.getClass(), new ArrayList<>());