Prevent menu items from showing on split tasks

This CL changes the TaskShortcutFactory for SCREENSHOT and MODAL so that the associated menu options ("Screenshot" and "Select") don't show up on split tasks. These actions are not fully supported on splitscreen tiles (they will only work on one of the two apps), so we disable them.

Bug: 327434215
Flag: N/A
Test: Manual
Change-Id: I121a9c28fa7570f10e13be2de6489182e3362cfc
(cherry picked from commit 6a60c3b113)
Merged-In: I121a9c28fa7570f10e13be2de6489182e3362cfc

quickstep/src/com/android/quickstep/TaskOverlayFactory.java

@@ -82,9 +82,10 @@ public class TaskOverlayFactory implements ResourceBasedOverride {
         boolean isTablet = activity.getDeviceProfile().isTablet;
 
         boolean isGridOnlyOverview = isTablet && Flags.enableGridOnlyOverview();
-        // Add overview actions to the menu when in in-place rotate landscape mode, or in
-        // grid-only overview.
-        if ((!canLauncherRotate && isInLandscape) || isGridOnlyOverview) {
+        // Add overview actions to the menu when:
+        // - single task is showing
+        // - in in-place rotate landscape mode, or in grid-only overview.
+        if (!hasMultipleTasks && ((!canLauncherRotate && isInLandscape) || isGridOnlyOverview)) {
             // Add screenshot action to task menu.
             List<SystemShortcut> screenshotShortcuts = TaskShortcutFactory.SCREENSHOT
                     .getShortcuts(activity, taskContainer);