Fix flaky testMultiWindowFocusHandleOnDifferentUiThread

The reason of this flaky test is CL[1] which block untrusted
touches in enforcing mode.

This flaky test is fixed after CL[2], remove the FlakyTest
annotation.

[1]: I709711e60f5f4f563e018ee079ef89418e161d14
[2]: Iea970e6a4793dd991e2a666c04bb508d7fa240ed

Fix: 176926757
Test: atest --iterations 100
FocusHandlingTest#testMultiWindowFocusHandleOnDifferentUiThread

Change-Id: Ia6f2324016913be3bc623a7805e06648ed4c7c9a
(cherry picked from commit 59cfe3b541b27f4b9a702256f294be9fae960e41)
diff --git a/tests/inputmethod/src/android/view/inputmethod/cts/FocusHandlingTest.java b/tests/inputmethod/src/android/view/inputmethod/cts/FocusHandlingTest.java
index febccb7..116e8a9 100644
--- a/tests/inputmethod/src/android/view/inputmethod/cts/FocusHandlingTest.java
+++ b/tests/inputmethod/src/android/view/inputmethod/cts/FocusHandlingTest.java
@@ -513,7 +513,6 @@
 
     @AppModeFull(reason = "Instant apps cannot hold android.permission.SYSTEM_ALERT_WINDOW")
     @Test
-    @FlakyTest(bugId = 176926757)
     public void testMultiWindowFocusHandleOnDifferentUiThread() throws Exception {
         final Instrumentation instrumentation = InstrumentationRegistry.getInstrumentation();
         try (CloseOnce session = CloseOnce.of(new ServiceSession(instrumentation.getContext()));