Enable creating task shortcuts without inheriting

Bug: 117888000
Test: manual test with a prototype
Change-Id: Ib7edab875c18b60cafc912325bd4e1fa0b7f515c
diff --git a/quickstep/src/com/android/quickstep/TaskSystemShortcut.java b/quickstep/src/com/android/quickstep/TaskSystemShortcut.java
index 66ce4c3..a8eb321 100644
--- a/quickstep/src/com/android/quickstep/TaskSystemShortcut.java
+++ b/quickstep/src/com/android/quickstep/TaskSystemShortcut.java
@@ -63,7 +63,7 @@
 
     protected T mSystemShortcut;
 
-    protected TaskSystemShortcut(T systemShortcut) {
+    public TaskSystemShortcut(T systemShortcut) {
         super(systemShortcut);
         mSystemShortcut = systemShortcut;
     }