Correctly handle a case when there are no preloaded apps

am: 28ba2898ce

Change-Id: Iac5083931ff13a81bd631915d198872690252310

services/retaildemo/java/com/android/server/retaildemo/PreloadAppsInstaller.java

@@ -67,10 +67,11 @@ class PreloadAppsInstaller {
 
     void installApps(int userId) {
         File[] files = preloadsAppsDirectory.listFiles();
+        AppInstallCounter counter = new AppInstallCounter(mContext, userId);
         if (ArrayUtils.isEmpty(files)) {
+            counter.setExpectedAppsCount(0);
             return;
         }
-        AppInstallCounter counter = new AppInstallCounter(mContext, userId);
         int expectedCount = 0;
         for (File file : files) {
             String apkName = file.getName();