Recenter upon notification from VrCore

Bug: 36201389
Test: manual on device
Change-Id: I690b70130e45732f052d136bedd587ddbf9493b4
diff --git a/services/vr/vr_window_manager/shell_view.cpp b/services/vr/vr_window_manager/shell_view.cpp
index c270be2..fba599f 100644
--- a/services/vr/vr_window_manager/shell_view.cpp
+++ b/services/vr/vr_window_manager/shell_view.cpp
@@ -378,6 +378,9 @@
           case 0x3:
             OnTouchpadButton(false, AMOTION_EVENT_BUTTON_BACK);
             break;
+          case 0x4:
+            should_recenter_ = true;
+            break;
           case 0x9:
             OnClick(true);
             break;