Add storage_summary_donut above ProfileSelectStorageFragment

- Modify ProfileSelectFragment to support add preference xml in the
top, and tabLayout below the preferences. Base preference layout is
dummy_preference_screen.xml which contains no preference.
ProfileSelectStorageFragment contains StorageSummaryDonutPreference
above the tabLayout.
- Make StorageSummaryDonutPreferenceController self workable without
StorageDashboardFragment dependence.
- Rename inactive_apps.xml to dummy_preference_screen.xml
- Move ShadowPrivateStorageInfo from LowStorageSliceTest

Bug: 141601408
Test: manual
Change-Id: Ide12840dc81bb104f328e230ecda5d35bba01d7a

tests/robotests/src/com/android/settings/testutils/shadow/ShadowPrivateStorageInfo.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2019 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.testutils.shadow;
+
+import com.android.settingslib.deviceinfo.PrivateStorageInfo;
+import com.android.settingslib.deviceinfo.StorageVolumeProvider;
+
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+import org.robolectric.annotation.Resetter;
+
+@Implements(PrivateStorageInfo.class)
+public class ShadowPrivateStorageInfo {
+
+    private static PrivateStorageInfo sPrivateStorageInfo = null;
+
+    @Resetter
+    public static void reset() {
+        sPrivateStorageInfo = null;
+    }
+
+    @Implementation
+    protected static PrivateStorageInfo getPrivateStorageInfo(
+            StorageVolumeProvider storageVolumeProvider) {
+        return sPrivateStorageInfo;
+    }
+
+    public static void setPrivateStorageInfo(
+            PrivateStorageInfo privateStorageInfo) {
+        sPrivateStorageInfo = privateStorageInfo;
+    }
+}