Align more prefs for icon space.

- Extend preference_category to support summary text
- Removed work_profile_category, used by account list
- align prefs in storage settings
- Use Preference instead of PrefScreen in xmls
- Use proper footer preference in NightDisplaySettings, BatterySaver,
  DataSaver, AutomaticStorageManage
- Remove WallOfTextPreference

Bug: 33775510
Test: visual
Change-Id: I28156b857ff5acac8746c42384dc03d5997ebd9d

src/com/android/settings/fuelgauge/BatterySaverSettings.java

@@ -78,7 +78,8 @@ public class BatterySaverSettings extends SettingsPreferenceFragment
         }
         mCreated = true;
         addPreferencesFromResource(R.xml.battery_saver_settings);
-
+        mFooterPreferenceMixin.createFooterPreference()
+                .setTitle(com.android.internal.R.string.battery_saver_description);
         mContext = getActivity();
         mSwitchBar = ((SettingsActivity) mContext).getSwitchBar();
         mSwitch = mSwitchBar.getSwitch();