Use FooterPreference in xml explicitly

Removed the FooterPreferenceMixin from the FeatureFlagsDashboard page.

Fixes: 139046148
Test: manual test
Change-Id: I6363f265a9c8b996141b7d7547c450cb70e2a7cd

res/xml/feature_flags_settings.xml

@@ -25,4 +25,10 @@
         android:layout="@layout/preference_category_no_label"
         android:title="@string/summary_placeholder"
         settings:controller="com.android.settings.development.featureflags.FeatureFlagsPreferenceController" />
+
+    <com.android.settingslib.widget.FooterPreference
+        android:key="feature_flag_footer"
+        android:title="@string/experimental_category_title"
+        android:selectable="false"
+        settings:searchable="false"/>
 </PreferenceScreen>

src/com/android/settings/development/featureflags/FeatureFlagFooterPreferenceController.java

@@ -1,50 +0,0 @@
-/*
- * Copyright (C) 2018 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.development.featureflags;
-
-import android.content.Context;
-
-import com.android.settings.R;
-import com.android.settings.core.BasePreferenceController;
-import com.android.settingslib.core.lifecycle.LifecycleObserver;
-import com.android.settingslib.core.lifecycle.events.OnStart;
-import com.android.settingslib.widget.FooterPreferenceMixinCompat;
-
-public class FeatureFlagFooterPreferenceController extends BasePreferenceController
-        implements LifecycleObserver, OnStart {
-
-    private FooterPreferenceMixinCompat mFooterMixin;
-
-    public FeatureFlagFooterPreferenceController(Context context) {
-        super(context, "feature_flag_footer_pref");
-    }
-
-    public void setFooterMixin(FooterPreferenceMixinCompat mixin) {
-        mFooterMixin = mixin;
-    }
-
-    @Override
-    public int getAvailabilityStatus() {
-        return AVAILABLE;
-    }
-
-    @Override
-    public void onStart() {
-        mFooterMixin.createFooterPreference()
-                .setTitle(R.string.experimental_category_title);
-    }
-}

src/com/android/settings/development/featureflags/FeatureFlagsDashboard.java

@@ -24,8 +24,6 @@ import com.android.settings.R;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.search.BaseSearchIndexProvider;
 import com.android.settings.search.Indexable;
-import com.android.settingslib.core.AbstractPreferenceController;
-import com.android.settingslib.core.lifecycle.Lifecycle;
 import com.android.settingslib.development.DevelopmentSettingsEnabler;
 import com.android.settingslib.search.SearchIndexable;
 
@@ -55,7 +53,6 @@ public class FeatureFlagsDashboard extends DashboardFragment {
     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
-        use(FeatureFlagFooterPreferenceController.class).setFooterMixin(mFooterPreferenceMixin);
     }
 
     @Override
@@ -63,23 +60,6 @@ public class FeatureFlagsDashboard extends DashboardFragment {
         return 0;
     }
 
-    @Override
-    protected List<AbstractPreferenceController> createPreferenceControllers(Context context) {
-        return buildPrefControllers(context, getSettingsLifecycle());
-    }
-
-    private static List<AbstractPreferenceController> buildPrefControllers(Context context,
-            Lifecycle lifecycle) {
-        final List<AbstractPreferenceController> controllers = new ArrayList<>();
-        final FeatureFlagFooterPreferenceController footerController =
-                new FeatureFlagFooterPreferenceController(context);
-        if (lifecycle != null) {
-            lifecycle.addObserver(footerController);
-        }
-        controllers.add(footerController);
-        return controllers;
-    }
-
     public static final Indexable.SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
             new BaseSearchIndexProvider() {
                 @Override
@@ -97,11 +77,5 @@ public class FeatureFlagsDashboard extends DashboardFragment {
                 protected boolean isPageSearchEnabled(Context context) {
                     return DevelopmentSettingsEnabler.isDevelopmentSettingsEnabled(context);
                 }
-
-                @Override
-                public List<AbstractPreferenceController> createPreferenceControllers(
-                        Context context) {
-                    return buildPrefControllers(context, null /* lifecycle */);
-                }
             };
 }