Upstream allowing multiple toasts for focused app

Test:The topic contains CTS tests that pass

Change-Id: I60515845f7c9be23887764bb1c59bf2b3301adc8
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 592eaec..505051f 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -1488,6 +1488,13 @@
 
     boolean canAddToastWindowForUid(int uid) {
         // We allow one toast window per UID being shown at a time.
+        // Also if the app is focused adding more than one toast at
+        // a time for better backwards compatibility.
+        final WindowState focusedWindowForUid = getWindow(w ->
+                w.mOwnerUid == uid && w.isFocused());
+        if (focusedWindowForUid != null) {
+            return true;
+        }
         final WindowState win = getWindow(w ->
                 w.mAttrs.type == TYPE_TOAST && w.mOwnerUid == uid && !w.mPermanentlyHidden
                 && !w.mWindowRemovalAllowed);