Extend tests to check Transient Taskbar Autohide

Bug: 260589084
Test: ab/I67000010134246487 on local device

Change-Id: Iad141fcbac54770810009e41082ab583cc3d260e
diff --git a/quickstep/tests/src/com/android/quickstep/TaplTestsTaskbar.java b/quickstep/tests/src/com/android/quickstep/TaplTestsTaskbar.java
index aed26d3..735c5e6 100644
--- a/quickstep/tests/src/com/android/quickstep/TaplTestsTaskbar.java
+++ b/quickstep/tests/src/com/android/quickstep/TaplTestsTaskbar.java
@@ -92,6 +92,7 @@
     @TaskbarModeSwitch(mode = TRANSIENT)
     public void testTransientLaunchApp() throws Exception {
         getTaskbar().getAppIcon(TEST_APP_NAME).launch(TEST_APP_PACKAGE);
+        mLauncher.getLaunchedAppState().assertTaskbarHidden();
     }
 
     @Test
@@ -140,6 +141,7 @@
     public void testTransientLaunchAppInSplitscreen() throws Exception {
         getTaskbar().getAppIcon(TEST_APP_NAME).dragToSplitscreen(
                 TEST_APP_PACKAGE, CALCULATOR_APP_PACKAGE);
+        mLauncher.getLaunchedAppState().assertTaskbarHidden();
     }
 
     @Test