Modify preference_list_fragment to support tabLayout

- Remove buttonBar because it is only used in PublicVolumeSettings
- Add tabLayout in preference_list_fragment.xml

Bug: 141601408
Test: manual
Change-Id: Ieb84ccf2e685a03abec7b07cb8f9f4b64ee475e0

src/com/android/settings/SettingsPreferenceFragment.java

@@ -110,7 +110,6 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
 
     @VisibleForTesting
     ViewGroup mPinnedHeaderFrameLayout;
-    private ViewGroup mButtonBar;
 
     private LayoutPreference mHeader;
 
@@ -141,7 +140,6 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
             Bundle savedInstanceState) {
         final View root = super.onCreateView(inflater, container, savedInstanceState);
         mPinnedHeaderFrameLayout = root.findViewById(R.id.pinned_header);
-        mButtonBar = root.findViewById(R.id.button_bar);
         return root;
     }
 
@@ -165,10 +163,6 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
         }
     }
 
-    public ViewGroup getButtonBar() {
-        return mButtonBar;
-    }
-
     public View setPinnedHeaderView(int layoutResId) {
         final LayoutInflater inflater = getActivity().getLayoutInflater();
         final View pinnedHeader =