Chaning the behavior of settings activity.

> Making all twoState prefs backed by content provider
> Using the stadard intent defined in N for settings
> Using SharedPrefsListener instead of LauncherProvider

Change-Id: I8272f54aa780bc0436e3d0aa89096a4bd2a9194f

src/com/android/launcher3/testing/LauncherExtension.java

@@ -126,10 +126,6 @@ public class LauncherExtension extends Launcher {
         public void bindAllApplications(ArrayList<AppInfo> apps) {
         }
 
-        @Override
-        public void onClickSettingsButton(View v) {
-        }
-
         @Override
         public void onWorkspaceLockedChanged() {
         }