Get display id from display instead of the display of root view

Since `getRootView()` will increase the execution time, use
`getDisplay()` instead.

Bug: 202825727
Test: manually
Change-Id: I22ef58cb39716433cd8e91200837ab49229ae3e1
(cherry picked from commit 6a06d8615f24769381e340a544c71d56a79ff25c)
diff --git a/quickstep/src/com/android/quickstep/views/TaskView.java b/quickstep/src/com/android/quickstep/views/TaskView.java
index 984b0ef..1d621dc 100644
--- a/quickstep/src/com/android/quickstep/views/TaskView.java
+++ b/quickstep/src/com/android/quickstep/views/TaskView.java
@@ -725,7 +725,8 @@
             TestLogging.recordEvent(
                     TestProtocol.SEQUENCE_MAIN, "startActivityFromRecentsAsync", mTask);
             ActivityOptionsWrapper opts =  mActivity.getActivityLaunchOptions(this, null);
-            opts.options.setLaunchDisplayId(getRootViewDisplayId());
+            opts.options.setLaunchDisplayId(
+                    getDisplay() == null ? DEFAULT_DISPLAY : getDisplay().getDisplayId());
             if (ActivityManagerWrapper.getInstance()
                     .startActivityFromRecents(mTask.key, opts.options)) {
                 RecentsView recentsView = getRecentsView();
@@ -766,7 +767,8 @@
             // Indicate success once the system has indicated that the transition has started
             ActivityOptions opts = ActivityOptionsCompat.makeCustomAnimation(
                     getContext(), 0, 0, () -> callback.accept(true), MAIN_EXECUTOR.getHandler());
-            opts.setLaunchDisplayId(getRootViewDisplayId());
+            opts.setLaunchDisplayId(
+                    getDisplay() == null ? DEFAULT_DISPLAY : getDisplay().getDisplayId());
             if (freezeTaskList) {
                 ActivityOptionsCompat.setFreezeRecentTasksList(opts);
             }