Adding a title to contentDesciption of the seekbar.
The title is helpful to indicate which seekbar user is changing when
talkback is enabled.
Also move SeekBarPreference from root package to widget packge.
Change-Id: I793f41c4902e350b6bc6d62761362779cc3722a9
Fix: 35421942
Test: make RunSettingsRoboTests
- 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
