Launch DesktopWallpaper in fullscreen

This CL ensures that DesktopWallpaperActivity is launched in fullscreen
regardless of the TDA’s windowing mode. Otherwise, it’s launched in
freeform mode on freeform-first devices.

Bug: 363857269
Bug: 361419732
Flag: EXEMPT bug fix
Test: manual
Change-Id: Ibbd4b6d914cda5cb34d0edc56630713f56bb3d46
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
index 33794d2..69c85ae 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
@@ -799,6 +799,7 @@
         val intent = Intent(context, DesktopWallpaperActivity::class.java)
         val options =
             ActivityOptions.makeBasic().apply {
+                launchWindowingMode = WINDOWING_MODE_FULLSCREEN
                 pendingIntentBackgroundActivityStartMode =
                     ActivityOptions.MODE_BACKGROUND_ACTIVITY_START_ALLOW_ALWAYS
             }