Ignore all launcher3 flaky test so that they come back online

Dashboards in: https://sites.google.com/corp/a/google.com/gnl/testing#h.p_ID_32

Bug: 256832045
Test: dashboard should not show flaky tests
Change-Id: I3e4bbf14c87e23b42a010a3cad046bb4852bd641

tests/src/com/android/launcher3/ui/widget/AddWidgetTest.java

@@ -33,6 +33,7 @@ import com.android.launcher3.ui.TestViewHelpers;
 import com.android.launcher3.util.rule.ShellCommandRule;
 import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
 
+import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -85,6 +86,7 @@ public class AddWidgetTest extends AbstractLauncherUiTest {
      * A custom shortcut is a 1x1 widget that launches a specific intent when user tap on it.
      * Custom shortcuts are replaced by deep shortcuts after api 25.
      */
+    @Ignore
     @Test
     @PortraitLandscape
     public void testDragCustomShortcut() throws Throwable {