Use the plural format for "See all COUNT apps"

Although there will never be only one app on the device, we still have
to use the plural format for the strings.

Fixes: 146513299
Test: rebuild and see the string in Apps&Notifications page.
Change-Id: I326be50cfddb605584390ebba57dbd06c0ac29b0

src/com/android/settings/applications/RecentAppsPreferenceController.java

@@ -117,7 +117,8 @@ public class RecentAppsPreferenceController extends BasePreferenceController
             @Override
             protected void onCountComplete(int num) {
                 mAppEntitiesController.setHeaderDetails(
-                        mContext.getString(R.string.see_all_apps_title, num));
+                        mContext.getResources().getQuantityString(R.plurals.see_all_apps_title,
+                                num, num));
                 mAppEntitiesController.apply();
             }
         }.execute();