SF: Identify virtual displays from proto

Used in flicker tests to ignore virtual displays
created for screen recording.

Test: winscope
Bug: 140855415
Change-Id: Icf344443b64f0cbedb2a8080fbd8a4b90a197741
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 21f3872..5f5f1f6 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4952,6 +4952,7 @@
         });
         LayerProtoHelper::writeTransformToProto(display->getTransform(),
                                                 displayProto->mutable_transform());
+        displayProto->set_is_virtual(display->isVirtual());
     }
 }