Add shell recents interface

- Add a shell component and interface for Launcher to use to get recent
  tasks including paired splits (pending integration w/ split controller)

Bug: 202740477
Test: atest WMShellUnitTests:com.android.wm.shell.recents.RecentTasksControllerTest

Signed-off-by: Winson Chung <winsonc@google.com>
Change-Id: I34d834061ed2391d89cf56d6a2fd262868707674
Merged-In: I34d834061ed2391d89cf56d6a2fd262868707674
diff --git a/libs/WindowManager/Shell/Android.bp b/libs/WindowManager/Shell/Android.bp
index 3ba1a34..73c2e8b 100644
--- a/libs/WindowManager/Shell/Android.bp
+++ b/libs/WindowManager/Shell/Android.bp
@@ -38,6 +38,7 @@
     path: "src",
 }
 
+// Sources that have no dependencies that can be used directly downstream of this library
 filegroup {
     name: "wm_shell_util-sources",
     srcs: [
@@ -46,6 +47,7 @@
     path: "src",
 }
 
+// Aidls which can be used directly downstream of this library
 filegroup {
     name: "wm_shell-aidls",
     srcs: [