Added stack id to TaskRecord dump.

Bug: 22812470
Change-Id: Ic8f3550e61ad1cf175423abe900c5f60686338a2
diff --git a/services/core/java/com/android/server/am/TaskRecord.java b/services/core/java/com/android/server/am/TaskRecord.java
index 78f9f18..7e2ad296 100644
--- a/services/core/java/com/android/server/am/TaskRecord.java
+++ b/services/core/java/com/android/server/am/TaskRecord.java
@@ -1223,6 +1223,9 @@
         if (lastDescription != null) {
             pw.print(prefix); pw.print("lastDescription="); pw.println(lastDescription);
         }
+        if (stack != null) {
+            pw.print(prefix); pw.print("stackId="); pw.println(stack.mStackId);
+        }
         pw.print(prefix); pw.print("hasBeenVisible="); pw.print(hasBeenVisible);
                 pw.print(" mResizeable="); pw.print(mResizeable);
                 pw.print(" firstActiveTime="); pw.print(lastActiveTime);