Demoting WorkProfileTest#testEdu from presubmit due to high flakiness

Test: presubmit
Bug: 243688989
Change-Id: Ib477e9f749a6f7117008d65316f32080c719167c

tests/src/com/android/launcher3/ui/WorkProfileTest.java

@@ -177,6 +177,7 @@ public class WorkProfileTest extends AbstractLauncherUiTest {
     }
 
     @Test
+    @Stability(flavors = LOCAL | PLATFORM_POSTSUBMIT) // b/243688989
     public void testEdu() {
         assumeTrue(mWorkProfileSetupSuccessful);
         waitForWorkTabSetup();