Hide split screen option if app doesn't support it

Bug: 73120439
Bug: 70294936
Change-Id: I3cfb665d54f59222936aa6f735275b692b0a7e54
diff --git a/quickstep/src/com/android/quickstep/TaskSystemShortcut.java b/quickstep/src/com/android/quickstep/TaskSystemShortcut.java
index d8ba186..9c3f0d4 100644
--- a/quickstep/src/com/android/quickstep/TaskSystemShortcut.java
+++ b/quickstep/src/com/android/quickstep/TaskSystemShortcut.java
@@ -23,7 +23,6 @@
 import android.os.Looper;
 import android.os.RemoteException;
 import android.os.UserHandle;
-import android.provider.Settings;
 import android.util.Log;
 import android.view.View;
 
@@ -101,8 +100,11 @@
             if (launcher.getDeviceProfile().inMultiWindowMode()) {
                 return null;
             }
+            final Task task  = taskView.getTask();
+            if (!task.isDockable) {
+                return null;
+            }
             return (v -> {
-                Task task  = taskView.getTask();
                 final ActivityOptions options = ActivityOptionsCompat.makeSplitScreenOptions(true);
                 final Consumer<Boolean> resultCallback = success -> {
                     if (success) {