Use UiThreadTest annotation

Change-Id: If6f2dcfde30855a04acd6effebefa336825f7247
diff --git a/system/AppUsageStatistics/Application/tests/src/com/example/android/appusagestatistics/AppUsageStatisticsFragmentTests.java b/system/AppUsageStatistics/Application/tests/src/com/example/android/appusagestatistics/AppUsageStatisticsFragmentTests.java
index bcffdea..68f9711 100644
--- a/system/AppUsageStatistics/Application/tests/src/com/example/android/appusagestatistics/AppUsageStatisticsFragmentTests.java
+++ b/system/AppUsageStatistics/Application/tests/src/com/example/android/appusagestatistics/AppUsageStatisticsFragmentTests.java
@@ -21,6 +21,7 @@
 import android.app.usage.UsageStats;
 import android.app.usage.UsageStatsManager;
 import android.test.ActivityInstrumentationTestCase2;
+import android.test.UiThreadTest;
 
 import java.util.List;
 
@@ -81,16 +82,11 @@
         assertNotNull(usageStatsList);
     }
 
+    @UiThreadTest
     public void testUpdateAppsList() {
-        final List<UsageStats> usageStatsList = mTestFragment
+        List<UsageStats> usageStatsList = mTestFragment
                 .getUsageStatistics(UsageStatsManager.INTERVAL_DAILY);
-        mTestActivity.runOnUiThread(new Runnable() {
-            @Override
-            public void run() {
-                mTestFragment.updateAppsList(usageStatsList);
-            }
-        });
-        getInstrumentation().waitForIdleSync();
+        mTestFragment.updateAppsList(usageStatsList);
 
         // The result depends on if the app is granted the access to App usage statistics.
         if (usageStatsList.size() == 0) {