DO NOT MERGE: Revert "Add summary text to Display->Brightness level."

This reverts commit 03ee253701.

The change does not work properly and is causing confusion.

Bug: 36650108

Change-Id: I00acced742b20e215c869ed58eb8750c654f5742

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

@@ -1,49 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
- * except in compliance with the License. You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software distributed under the
- * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied. See the License for the specific language governing
- * permissions and limitations under the License.
- */
-package com.android.settings.display;
-
-import static android.provider.Settings.System.SCREEN_BRIGHTNESS;
-
-import android.content.Context;
-import android.provider.Settings;
-import android.support.v7.preference.Preference;
-import com.android.settings.core.PreferenceController;
-import java.text.NumberFormat;
-
-public class BrightnessLevelPreferenceController extends PreferenceController {
-
-    private static final String KEY_BRIGHTNESS = "brightness";
-
-    public BrightnessLevelPreferenceController(Context context) {
-        super(context);
-    }
-
-    @Override
-    public boolean isAvailable() {
-        return true;
-    }
-
-    @Override
-    public String getPreferenceKey() {
-        return KEY_BRIGHTNESS;
-    }
-
-    @Override
-    public void updateState(Preference preference) {
-        final double brightness = Settings.System.getInt(mContext.getContentResolver(),
-            SCREEN_BRIGHTNESS, 0);
-        preference.setSummary(NumberFormat.getPercentInstance().format(brightness / 255));
-    }
-
-}