Add wallpaper to sync set during collection

Prevent wallpaper flickers caused by early changes in
visibility caused by operations not controlled by the transition

Fix: 283465374
Test: Manual, unlock device with fingerprint multiple times
Change-Id: I1e1f26db1889d7e9feb9a17b4be5fbcf5f3b0419

services/core/java/com/android/server/wm/Transition.java

@@ -613,12 +613,8 @@ class Transition implements BLASTSyncEngine.TransactionReadyListener {
             }
         }
         if (mParticipants.contains(wc)) return;
-        // Wallpaper is like in a static drawn state unless display may have changes, so exclude
-        // the case to reduce transition latency waiting for the unchanged wallpaper to redraw.
-        final boolean needSync = (!isWallpaper(wc) || mParticipants.contains(wc.mDisplayContent))
-                // Transient-hide may be hidden later, so no need to request redraw.
-                && !isInTransientHide(wc);
-        if (needSync) {
+        // Transient-hide may be hidden later, so no need to request redraw.
+        if (!isInTransientHide(wc)) {
             mSyncEngine.addToSyncSet(mSyncId, wc);
         }
         ChangeInfo info = mChanges.get(wc);

services/core/java/com/android/server/wm/WindowState.java

@@ -5665,7 +5665,7 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
         }
         if (mIsWallpaper) {
             // TODO(b/233286785): Add sync support to wallpaper.
-            return false;
+            return true;
         }
         // In the WindowContainer implementation we immediately mark ready
         // since a generic WindowContainer only needs to wait for its