Unfreeze the surface when the transition is done

The surface was not unfreeze if the WindowContainer is closing and
changing after [1].

Always check and unfreeze the surface if needed when the transition
is done.

[1] d19ad2a

Bug: 280754787
Test: click web link on chat while having a Meet call
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:f3a5c5892402916ca861c41319f21acb83bd1f83)
Merged-In: I98618477a828eb72b2173af6988e804471139e81
Change-Id: I98618477a828eb72b2173af6988e804471139e81

Author: Louis Chang

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

@@ -1396,6 +1396,9 @@ void checkAppWindowsReadyToShow() {
     }
 
     void onAppTransitionDone() {
+        if (mSurfaceFreezer.hasLeash()) {
+            mSurfaceFreezer.unfreeze(getSyncTransaction());
+        }
         for (int i = mChildren.size() - 1; i >= 0; --i) {
             final WindowContainer wc = mChildren.get(i);
             wc.onAppTransitionDone();