Follow O patterns for a11y settings

Move the summary for the toggled features to a footer.
Make the settings appear as a preference.

Bug: 36780887
Test: Start settings and observe the new UI looks a lot
like the mocks referenced in the bug. Also added unit
test to verify that summary text shows up.

Change-Id: I1d002b194991d0901ecb27198ba5de73bd23a5a9

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

@@ -211,6 +211,18 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
 
     private DevicePolicyManager mDpm;
 
+    /**
+     * Check if the color transforms are color accelerated. Some transforms are experimental only
+     * on non-accelerated platforms due to the performance implications.
+     *
+     * @param context The current context
+     * @return
+     */
+    public static boolean isColorTransformAccelerated(Context context) {
+        return context.getResources()
+                .getBoolean(com.android.internal.R.bool.config_setColorTransformAccelerated);
+    }
+
     @Override
     public int getMetricsCategory() {
         return MetricsEvent.ACCESSIBILITY;
@@ -618,11 +630,6 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
         updateAccessibilityShortcut(mAccessibilityShortcutPreferenceScreen);
     }
 
-    private boolean isColorTransformAccelerated(Context context) {
-        return context.getResources()
-                .getBoolean(com.android.internal.R.bool.config_setColorTransformAccelerated);
-    }
-
     private void updateMagnificationSummary(Preference pref) {
         final boolean tripleTapEnabled = Settings.Secure.getInt(getContentResolver(),
                 Settings.Secure.ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED, 0) == 1;