Implement dream complication settings.

This component allows the user to select dream complications to
enable/disable.

Bug: 215703483
Test: locally on device
Change-Id: I03dd9d67b4aeb3f41885b42391d97c18bd7465f6

tests/robotests/src/com/android/settings/dream/DreamPickerControllerTest.java

@@ -65,10 +65,7 @@ public class DreamPickerControllerTest {
     }
 
     private DreamPickerController buildController() {
-        final DreamPickerController controller = new DreamPickerController(
-                mContext,
-                /* preferenceKey= */ "test",
-                mBackend);
+        final DreamPickerController controller = new DreamPickerController(mContext, mBackend);
         controller.displayPreference(mScreen);
         return controller;
     }