Fix egregious state check for window focusability.

- The original check should have not assumed that these are only app
  windows.

Bug: 63614176
Test: Ensure that you can unlock with password
Change-Id: I71a9959378bbd98a8ed6715d67119d38c3daceb5

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

@@ -1970,7 +1970,7 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
             return false;
         }
 
-        final boolean windowsAreFocusable = mAppToken != null && mAppToken.windowsAreFocusable();
+        final boolean windowsAreFocusable = mAppToken == null || mAppToken.windowsAreFocusable();
         if (!windowsAreFocusable) {
             // This window can't be an IME target if the app's windows should not be focusable.
             return false;