Mark wm tests as flaky

Bug: 74078662
Test: self
Change-Id: I286cde4d5f00591a049c3d972436e81ed815c36c
diff --git a/services/tests/servicestests/src/com/android/server/wm/WindowStateTests.java b/services/tests/servicestests/src/com/android/server/wm/WindowStateTests.java
index 74c72bf..33a248d 100644
--- a/services/tests/servicestests/src/com/android/server/wm/WindowStateTests.java
+++ b/services/tests/servicestests/src/com/android/server/wm/WindowStateTests.java
@@ -21,6 +21,7 @@
 import org.junit.runner.RunWith;
 
 import android.platform.test.annotations.Presubmit;
+import android.support.test.filters.FlakyTest;
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
 
@@ -52,6 +53,7 @@
  * atest FrameworksServicesTests:com.android.server.wm.WindowStateTests
  */
 @SmallTest
+@Flaky(bugId = 74078662)
 @Presubmit
 @RunWith(AndroidJUnit4.class)
 public class WindowStateTests extends WindowTestsBase {