Use HTML text preference for rich content

Implements for Color Correction, Color Inversion, and Magnify

Bug: 148837311
Test: Manual test
Change-Id: I5e5b311b6ae8e42cca3ef9048c8b8b0de52d13bc

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

@@ -330,9 +330,6 @@ public class ToggleAccessibilityServicePreferenceFragment extends
                 .appendPath(String.valueOf(animatedImageRes))
                 .build();
 
-        // Settings html description.
-        mHtmlDescription = arguments.getCharSequence(AccessibilitySettings.EXTRA_HTML_DESCRIPTION);
-
         // Get Accessibility service name.
         mPackageName = getAccessibilityServiceInfo().getResolveInfo().loadLabel(
                 getPackageManager());