Reset logging name of Task at the end of setIntent

In case ProtoLog is enabled that evaluates "this.toString"
too early, which caches the intermediate states in the string.

Bug: 328114157
Test: Start dream activity from Screen saver Settings.
      "adb shell dumpsys activity activities" should show
      the task with "type=dream".
Change-Id: I21f8cf0f3d6d43e762bb45d8c5d6374eaae58378
diff --git a/services/core/java/com/android/server/wm/Task.java b/services/core/java/com/android/server/wm/Task.java
index 1353ff0..df2d80d 100644
--- a/services/core/java/com/android/server/wm/Task.java
+++ b/services/core/java/com/android/server/wm/Task.java
@@ -978,7 +978,6 @@
         }
         effectiveUid = info.applicationInfo.uid;
         mIsEffectivelySystemApp = info.applicationInfo.isSystemApp();
-        stringName = null;
 
         if (info.targetActivity == null) {
             if (_intent != null) {
@@ -1045,6 +1044,7 @@
             updateTaskDescription();
         }
         mSupportsPictureInPicture = info.supportsPictureInPicture();
+        stringName = null;
 
         // Re-adding the task to Recents once updated
         if (inRecents) {