Focus the first task after the desktop task when launching overview from KQS

Flag: LEGACY ENABLE_KEYBOARD_QUICK_SWITCH ENABLED
Flag: ACONFIG com.android.window.flags.enable_desktop_windowing_mode DEVELOPMENT
Fixes: 327420683
Test: opened overview using KQS
Change-Id: I9395ad6065844bf5f5007180cd8c3f80573ee473

quickstep/src/com/android/launcher3/taskbar/KeyboardQuickSwitchViewController.java

@@ -138,7 +138,7 @@ public class KeyboardQuickSwitchViewController {
         // views have been added in the KeyboardQuickSwitchView.
         GroupTask task = mControllerCallbacks.getTaskAt(index);
         if (task == null) {
-            return Math.max(0, index);
+            return mOnDesktop ? 1 : Math.max(0, index);
         }
         if (mControllerCallbacks.isTaskRunning(task)) {
             // Ignore attempts to run the selected task if it is already running.