Zen: Move zen mode preference to switch bar.

- Add summary line support to SwitchBar.
 - Remove obsolete strings.
 - Wire up switchbar to zen mode w/ dialog prompt.
 - Remove obsolete callback pref helper.

Bug: 20064962
Change-Id: Ifede00b5d43d441ccd94db96bd2796bc57d1a990

src/com/android/settings/notification/ZenModePrioritySettings.java

@@ -132,7 +132,11 @@ public class ZenModePrioritySettings extends ZenModeSettingsBase implements Inde
     }
 
     @Override
-    protected void updateControls() {
+    protected void onZenModeConfigChanged() {
+        updateControls();
+    }
+
+    private void updateControls() {
         mDisableListeners = true;
         if (mCalls != null) {
             mCalls.setChecked(mConfig.allowCalls);