SurfaceFlinger: plumb composer 2.4 onSeamlessPossible

Plumb onSeamlessPossible callback to SurfaceFlinger.

Test: rev up composer to 2.4
Bug: 141329414
Change-Id: I2166b8ea066002c76781aacbcc985f85f7c255a8
diff --git a/libs/vr/libvrflinger/hardware_composer.cpp b/libs/vr/libvrflinger/hardware_composer.cpp
index 188ac6b..b771538 100644
--- a/libs/vr/libvrflinger/hardware_composer.cpp
+++ b/libs/vr/libvrflinger/hardware_composer.cpp
@@ -1215,6 +1215,12 @@
   return Void();
 }
 
+Return<void> HardwareComposer::ComposerCallback::onSeamlessPossible(
+    Hwc2::Display /*display*/) {
+  LOG_ALWAYS_FATAL("Unexpected onSeamlessPossible callback");
+  return Void();
+}
+
 void HardwareComposer::ComposerCallback::SetVsyncService(
     const sp<VsyncService>& vsync_service) {
   std::lock_guard<std::mutex> lock(mutex_);