Add storage dashborad page.

Refactor shared dashboard page display logic between storage and
system page.

Bug: 31800690
Test: RunSettingsRoboTests

Change-Id: I7eb86f590b79ab871bdb383fb2f5326790beb193

src/com/android/settings/deviceinfo/ManageStoragePreferenceController.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2016 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.deviceinfo;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.R;
+import com.android.settings.core.PreferenceController;
+
+public class ManageStoragePreferenceController extends PreferenceController {
+
+    public static final String KEY_MANAGE_STORAGE = "pref_manage_storage";
+
+    public ManageStoragePreferenceController(Context context) {
+        super(context);
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        if (!isAvailable()) {
+            removePreference(screen, KEY_MANAGE_STORAGE);
+        }
+    }
+
+    @Override
+    public boolean handlePreferenceTreeClick(Preference preference) {
+        return false;
+    }
+
+    /**
+     * Whether a preference should be available on screen.
+     */
+    private boolean isAvailable() {
+        return mContext.getResources().getBoolean(R.bool.config_storage_manager_settings_enabled);
+    }
+}
+