Fix WindowContext cannot receive global config

... change on secondary display.

Previously we listen to #onRequestedOverrideConfigurationChanged() to
receive config changes, which only propagate callbacks if there's a
requested override configuration. This CL changes to listen to
 #onMergedOverrideConfigurationChanged() to ensure every config change
will propagate to WindowContext.

fixes: 185190979
Test: atest WindowContextTests

Change-Id: I0299a2795bd0b009ec2291a36aa1c87e163222b7

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

@@ -227,7 +227,7 @@ class WindowContextListenerController {
         }
 
         @Override
-        public void onRequestedOverrideConfigurationChanged(Configuration overrideConfiguration) {
+        public void onMergedOverrideConfigurationChanged(Configuration mergedOverrideConfig) {
             reportConfigToWindowTokenClient();
         }