Add infra for battery tip

This cl adds the basic structure for battery tip:
1. BaseBatteryTip: Model class to represent the tip and build
preference and dialog
2. SummaryTip: Display a general battery summary(i.e. your battery
is good..)
3. BatteryTipLoader: AsyncLoader to load the battery tips.
4. BatteryTipPreferenceController: preference controller for
preference group to display battery tips

This cl also:
1. Remove the anomaly code in PowerUsageSummary and we will add it
to app restriction in future.
2. Add preference_category_no_title.xml to avoid the extra 32dp
blank at the top.

Bug: 70570352
Test: RunSettingsRoboTests
Change-Id: If91a553888e2eb91d55fb1d0d7bbea69652f144c

src/com/android/settings/fuelgauge/batterytip/BatteryTipPreferenceController.java

@@ -0,0 +1,125 @@
+/*
+ * 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.fuelgauge.batterytip;
+
+import android.content.Context;
+import android.support.annotation.VisibleForTesting;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceGroup;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.core.BasePreferenceController;
+import com.android.settings.fuelgauge.batterytip.tips.BatteryTip;
+import com.android.settings.fuelgauge.batterytip.tips.SummaryTip;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Controller in charge of the battery tip group
+ */
+public class BatteryTipPreferenceController extends BasePreferenceController {
+    private BatteryTipListener mBatteryTipListener;
+    private List<BatteryTip> mBatteryTips;
+    private Map<String, BatteryTip> mBatteryTipMap;
+    @VisibleForTesting
+    PreferenceGroup mPreferenceGroup;
+    @VisibleForTesting
+    Context mPrefContext;
+
+    public BatteryTipPreferenceController(Context context, String preferenceKey) {
+        this(context, preferenceKey, null);
+    }
+
+    public BatteryTipPreferenceController(Context context, String preferenceKey,
+            BatteryTipListener batteryTipListener) {
+        super(context, preferenceKey);
+        mBatteryTipListener = batteryTipListener;
+        mBatteryTipMap = new HashMap<>();
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return AVAILABLE;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPrefContext = screen.getContext();
+        mPreferenceGroup = (PreferenceGroup) screen.findPreference(getPreferenceKey());
+
+        // Add summary tip in advance to avoid UI flakiness
+        final SummaryTip summaryTip = new SummaryTip(BatteryTip.StateType.NEW);
+        mPreferenceGroup.addPreference(summaryTip.buildPreference(mPrefContext));
+    }
+
+    public void updateBatteryTips(List<BatteryTip> batteryTips) {
+        if (mBatteryTips == null) {
+            mBatteryTips = batteryTips;
+        } else {
+            // mBatteryTips and batteryTips always have the same length and same sequence.
+            for (int i = 0, size = batteryTips.size(); i < size; i++) {
+                mBatteryTips.get(i).updateState(batteryTips.get(i));
+            }
+        }
+
+        //TODO(b/70570352): try to reuse the existing preference rather than remove and add.
+        mPreferenceGroup.removeAll();
+        for (int i = 0, size = batteryTips.size(); i < size; i++) {
+            final BatteryTip batteryTip = mBatteryTips.get(i);
+            if (batteryTip.getState() != BatteryTip.StateType.INVISIBLE) {
+                final Preference preference = batteryTip.buildPreference(mPrefContext);
+                mBatteryTipMap.put(preference.getKey(), batteryTip);
+                mPreferenceGroup.addPreference(preference);
+            }
+        }
+    }
+
+    @Override
+    public boolean handlePreferenceTreeClick(Preference preference) {
+        final BatteryTip batteryTip = mBatteryTipMap.get(preference.getKey());
+        if (batteryTip != null) {
+            if (batteryTip.shouldShowDialog()) {
+                // build and show the dialog
+            } else {
+                batteryTip.action();
+                if (mBatteryTipListener != null) {
+                    mBatteryTipListener.onBatteryTipHandled(batteryTip);
+                }
+            }
+
+            return true;
+        }
+
+        return super.handlePreferenceTreeClick(preference);
+    }
+
+    /**
+     * Listener to give the control back to target fragment
+     */
+    public interface BatteryTipListener {
+        /**
+         * This method is invoked once battery tip is handled, then target fragment could do
+         * extra work.
+         *
+         * @param batteryTip that has been handled
+         */
+        void onBatteryTipHandled(BatteryTip batteryTip);
+    }
+}