Remove flaky annotation

The flakewas fixed by ag/15353756, so remove the annotation.

Bug: 194242735
Test: atest ActivityThreadTest
Change-Id: Ia6e3eda250a0b54a2027d16f6e51887c85ac8f95

core/tests/coretests/src/android/app/activity/ActivityThreadTest.java

@@ -286,7 +286,6 @@ public class ActivityThreadTest {
     }
 
     @Test
-    @FlakyTest(bugId = 194242735)
     public void testHandleActivityConfigurationChanged_EnsureUpdatesProcessedInOrder()
             throws Exception {
         final TestActivity activity = mActivityTestRule.launchActivity(new Intent());