Fix onCurrentVrActivityChanged callbacks.

Bug: 36503317

Test: Use controller in a 3P VR application.

Change-Id: I1b11785077183c719e19f4f496677dba79e42dab
diff --git a/services/core/java/com/android/server/vr/VrManagerService.java b/services/core/java/com/android/server/vr/VrManagerService.java
index 5bcdd4c..e1df0ba 100644
--- a/services/core/java/com/android/server/vr/VrManagerService.java
+++ b/services/core/java/com/android/server/vr/VrManagerService.java
@@ -725,10 +725,10 @@
                 }
             }
 
-            mCurrentVrModeComponent = calling;
             if (calling != null && !Objects.equals(calling, mCurrentVrModeComponent)) {
                 sendUpdatedCaller = true;
             }
+            mCurrentVrModeComponent = calling;
 
             if (mCurrentVrModeUser != userId) {
                 mCurrentVrModeUser = userId;