[Material Next] Update accessibility tool footer style

1. Implement API extends Material Next FooterBarPreference and support Accessibility API for icons
2. Apply solutions to accessibility tools and framework tools in
accessibility settings page.
3. Apply DashboardFragment for Caption preference for xml parser

Bug: 185973304
Test: make RunSettingsRoboTests -j52
Change-Id: I6b80bc80190d6666e3fbcd462442a9f2c0e60bba

src/com/android/settings/accessibility/AccessibilityButtonFragment.java

@@ -17,7 +17,6 @@
 package com.android.settings.accessibility;
 
 import android.app.settings.SettingsEnums;
-import android.content.Context;
 
 import com.android.settings.R;
 import com.android.settings.dashboard.DashboardFragment;
@@ -35,11 +34,6 @@ public class AccessibilityButtonFragment extends DashboardFragment {
         return R.xml.accessibility_button_settings;
     }
 
-    @Override
-    public void onAttach(Context context) {
-        super.onAttach(context);
-    }
-
     @Override
     protected String getLogTag() {
         return TAG;