Add utility to get all root tasks on a display

This is intended to replace getAllStackInfos for
task organization purposes.

Bug: 33381284
Test: updated TaskOrganizerTests
Change-Id: I1ff10de188218f1cd0b5638c297dffbf2a9a04a2
diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index 5f3e3a3..d3129f0 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -2795,6 +2795,7 @@
         }
     }
 
+    // TODO(148895075): deprecate and replace with task equivalents
     @Override
     public List<ActivityManager.StackInfo> getAllStackInfos() {
         enforceCallerIsRecentsOrHasPermission(MANAGE_ACTIVITY_STACKS, "getAllStackInfos()");
@@ -2821,6 +2822,7 @@
         }
     }
 
+    // TODO(148895075): deprecate and replace with task equivalents
     @Override
     public List<ActivityManager.StackInfo> getAllStackInfosOnDisplay(int displayId) {
         enforceCallerIsRecentsOrHasPermission(MANAGE_ACTIVITY_STACKS, "getAllStackInfos()");